1.
Sea snail
–
Sea snail is a common name for snails that normally live in saltwater, in other words marine gastropods. The taxonomic class Gastropoda also includes snails that live in habitats, such as land snails. Many species of sea snails are edible and exploited as food sources by humans, sea snails are marine gastropods with shells. Those marine gastropods with no shells, or only internal shells, are known by other common names, including sea slug, sea hare, nudibranch. The diversity within sea snails is enormous, many very different clades of gastropods are either dominated by, or consist exclusively of, sea snails. Because of this variability, generalization about the feeding, reproduction, habitat. Instead, individual clades, families, genera, or species must be assessed, the shells of most species of sea snails are spirally coiled. Some, though, have shells, and these are often referred to by the common name of limpets. In one unusual family, the shell of the snail has two hinged plates closely resembling those of a bivalve, this family is sometimes called the bivalved gastropods. Their shells are found in a variety of shapes and sizes and those of living species of sea snails range in size from Syrinx aruanus, the largest living shelled gastropod species at 91 cm, to minute species whose shells are less than 1 mm at adult size. Because the shells of sea snails are strong and durable in many cases, sea snails are a very large group of animals and a very diverse one. Most snails that live in saltwater respire using a gill or gills, a few species, though, have a lung, are intertidal and these air-breathing species include false limpets in the family Siphonariidae and another group of false limpets in the family Trimusculidae. Many, but not all sea snails have an operculum, a number of species of sea snails are used by humans for food, including abalone, conch, limpets, whelks and periwinkles including Littorina littorea. The shells of sea snails are found by humans as seashells commonly wash up on beaches. Because the shells of sea snails are attractive and durable, they have been used by humans to make necklaces. The shells of a few species of sea snails within the Vetigastropoda have a thick layer of nacre and have been used as a source of mother of pearl. Historically, the industry relied on these species for a number of years. The shells of sea snails are used for protection by many kinds of hermit crabs, a hermit crab carries the shell by grasping the central columella of the shell using claspers on the tip of its abdomen
Sea snail
–
A species of sea snail in its natural habitat: two individuals of the
wentletrap Epidendrium billeeanum with a mass of egg capsules in situ on their food source, a red cup
coral.
Sea snail
–
The shell of
Syrinx aruanus can be up to 91 cm long.
Sea snail
–
A
hermit crab occupying a shell of
Acanthina punctulata has been disturbed, and has retracted into the shell, using its claws to bar the entrance in the same way the snail used its
operculum.
2.
Land snail
–
A land snail is any of the numerous species of snail that live on land, as opposed to sea snails and freshwater snails. Land snail is the name for terrestrial gastropod mollusks that have shells. The majority of land snails are pulmonates and that is, they have a lung and breathe air. A minority however belong to more ancient lineages where their anatomy includes a gill. Many of these land snails live in habitats or microhabitats that are sometimes damp or wet. Land snails have a muscular foot, they use mucus to enable them to crawl over rough surfaces. Like other mollusks, land snails have a mantle, and they have one or two pairs of tentacles on their head and their internal anatomy includes a radula and a primitive brain. In terms of reproduction, the majority of land snails are hermaphrodite, tiny snails hatch out of the egg with a small shell in place, and the shell grows spirally as the soft parts gradually increase in size. Most land snails have shells that are right-handed in their coiling, Land snails move by gliding along on their muscular foot, which is lubricated with mucus and covered with epithelial cilia. This motion is powered by succeeding waves of contractions that move down the ventral of the foot. This muscular action is visible when a snail is crawling on the glass of a window or aquarium. Snails move at a low speed. Snails secrete mucus externally to keep their bodies from drying out. The mucus that land snails secrete with the leaves a slime trail behind them. Snails also have a mantle, a layer of tissue which covers all of the internal organs as they are grouped together in the visceral mass. The mantle also extends outward in flaps which reach to the edge of the shell and in some cases can cover the shell, the mantle is attached to the shell, and creates the shell and makes shell growth possible by secretion. A lack of calcium, or low pH in their surroundings, can result in thin, cracked, usually a snail can repair damage to its shell over time if its living conditions improve, but severe damage can be fatal. When retracted into their shells, many snails with gills are able to protect themselves with a door-like anatomical structure called an operculum, Land snails range greatly in size
Land snail
–
Helix pomatia, a species of air-breathing land snail
Land snail
–
Colonies of snails in Sicily.
Land snail
–
Cornu Aspersum (previously known as
Helix Aspersa) – the common garden snail
Land snail
–
The Teeth of a Snail from
Robert Hooke 's
Micrographia, 1665
3.
Slug
–
Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc. The word slug is often used as part of the common name of any gastropod mollusc that has no shell. Various taxonomic families of land slugs form part of quite different evolutionary lineages. Thus, the families of slugs are not closely related. The shell-less condition has arisen many times independently during the evolutionary past, of the six orders of Pulmonata, two – the Onchidiacea and Soleolifera – solely comprise slugs. A third family, the Sigmurethra, contains various clades of snails, the taxonomy of this group is in the process of being revised in light of DNA sequencing. It appears that pulmonates are paraphyletic and basal to the opisthobranchs, the family Ellobiidae are also polyphyletic. E. The upper pair is light sensing and has eyespots at the ends, mantle On top of the slug, behind the head, is the saddle-shaped mantle, and under this are the genital opening and anus. On one side of the mantle is an opening, which is easy to see when open. This opening is known as the pneumostome, tail The part of a slug behind the mantle is called the tail. Keel Some species of slugs, for example Tandonia budapestensis, have a prominent ridge running over their back along the middle of the tail and this ridge is called a keel. Foot The bottom side of a slug, which is flat, is called the foot, like almost all gastropods, a slug moves by rhythmic waves of muscular contraction on the underside of its foot. It simultaneously secretes a layer of mucus that it travels on, around the edge of the foot in some taxa is a structure called the foot fringe. Vestigial shell Most slugs retain a remnant of their shell, which is usually internalized and this organ generally serves as storage for calcium salts, often in conjunction with the digestive glands. An internal shell is present in the Limacidae and Parmacellidae, adult Philomycidae, Onchidiidae and Veronicellidae lack shells. Slugs bodies are made up mostly of water and, without a full-sized shell and they must generate protective mucus to survive. Many species are most active just after rain because of the moist ground, in drier conditions, they hide in damp places such as under tree bark, fallen logs, rocks and man-made structures, such as planters, to help retain body moisture. Like all other gastropods, they undergo torsion during development, Slugs produce two types of mucus, one is thin and watery, and the other thick and sticky
Slug
Slug
–
Various species of
British land slugs, including (from the top) the larger drawings:
Arion ater,
Kerry slug,
Limax maximus and
Limax flavus
Slug
–
An active
Ambigolimax slug in
Fremont, California
Slug
–
Deroceras juvenile with eggs
4.
Helix pomatia
–
In the English language it is called by the French name escargot when used in cooking. Although this species is prized as a food it is difficult to cultivate. Distribution of Helix pomatia includes, Southeastern and central Europe, Germany – Listed as a protected species in annex 1 of the Bundesartenschutzverordnung. Austria Czech Republic – least concern species, Its conservation status in 2004–2006 is favourable in the report for the European commission in accordance with the Habitats Directive, poland Slovakia Hungary Romania In southwestern Bulgaria up to an altitude of more than 1600 m. Northern and central Balkans Slovenia Croatia Bosnia & Herzegovina Serbia Republic Of Macedonia Western Europe, Great Britain, in the west and its common name in the UK is Roman snail because it was introduced to the island by the Romans during the Roman period. In England only, the Roman snail is a species under the Wildlife and Countryside Act 1981, making it illegal to kill, injure. Central France Belgium Netherlands Switzerland Northern Europe, Denmark – Listed as a protected species, Southern Sweden Norway Finland In central and southern parts of Sweden, Norway and Finland, isolated and relatively small populations occur. It is not native to countries, but is likely to have been imported by monks from Southern Europe during medieval times. The shell has five to six whorls, the apertural margin is white and slightly reflected in adult snails. The umbilicus is narrow and partly covered by the columellar margin. The width of the shell is 30–50 mm, the height of the shell is 30–45 mm. In southeastern Europe, H. pomatia lives in forests, open habitats, gardens, vineyards, especially along rivers, in central Europe, it occurs in open forests and shrubland on calcareous substrate. It prefers high humidity and lower temperatures, and needs loose soil for burrowing to hibernate and it lives up to 2100 m above sea level in the Alps, but usually below 2000 m. In the south of England, it is restricted to undisturbed grassy or bushy wastelands, usually not in gardens, it has a low reproduction rate, average distance of migration reaches 3. 5–6.0 m. Reproduction in central Europe begins at the end of May, reproduction Eggs are laid in June and July, in clutches of 40–65 eggs. The size of the egg is 5. 5–6.5 mm or 8.6 ×7.2 mm. Juveniles hatch after three to four weeks, and may consume their siblings under unfavourable climate conditions, maturity is reached after two to five years. The life span is up to 20 years, ten-year-old individuals are probably not uncommon in natural populations. The maximum lifespan is 35 years, during estivation or hibernation, this species creates a calcareous epiphragm to seal the opening of the shell
Helix pomatia
–
Helix pomatia
Helix pomatia
–
Cooked snails are called
escargot
Helix pomatia
–
View of a
shell of Helix pomatia
Helix pomatia
–
Helix pomatia (the larger snail) laying eggs)
5.
Taxonomy (biology)
–
Taxonomy is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. The exact definition of taxonomy varies from source to source, but the core of the remains, the conception, naming. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy, the broadest meaning of taxonomy is used here. The word taxonomy was introduced in 1813 by Candolle, in his Théorie élémentaire de la botanique, the term alpha taxonomy is primarily used today to refer to the discipline of finding, describing, and naming taxa, particularly species. In earlier literature, the term had a different meaning, referring to morphological taxonomy, ideals can, it may be said, never be completely realized. They have, however, a value of acting as permanent stimulants. Some of us please ourselves by thinking we are now groping in a beta taxonomy, turrill thus explicitly excludes from alpha taxonomy various areas of study that he includes within taxonomy as a whole, such as ecology, physiology, genetics, and cytology. He further excludes phylogenetic reconstruction from alpha taxonomy, thus, Ernst Mayr in 1968 defined beta taxonomy as the classification of ranks higher than species. This activity is what the term denotes, it is also referred to as beta taxonomy. How species should be defined in a group of organisms gives rise to practical and theoretical problems that are referred to as the species problem. The scientific work of deciding how to define species has been called microtaxonomy, by extension, macrotaxonomy is the study of groups at higher taxonomic ranks, from subgenus and above only, than species. While some descriptions of taxonomic history attempt to date taxonomy to ancient civilizations, earlier works were primarily descriptive, and focused on plants that were useful in agriculture or medicine. There are a number of stages in scientific thinking. Early taxonomy was based on criteria, the so-called artificial systems. Later came systems based on a complete consideration of the characteristics of taxa, referred to as natural systems, such as those of de Jussieu, de Candolle and Bentham. The publication of Charles Darwins Origin of Species led to new ways of thinking about classification based on evolutionary relationships and this was the concept of phyletic systems, from 1883 onwards. This approach was typified by those of Eichler and Engler, the advent of molecular genetics and statistical methodology allowed the creation of the modern era of phylogenetic systems based on cladistics, rather than morphology alone. Taxonomy has been called the worlds oldest profession, and naming and classifying our surroundings has likely been taking place as long as mankind has been able to communicate
Taxonomy (biology)
–
Title page of
Systema Naturae, Leiden, 1735
Taxonomy (biology)
–
Evolution of the
vertebrates at class level, width of spindles indicating number of families. Spindle diagrams are typical for
Evolutionary taxonomy
Taxonomy (biology)
–
The same relationship, expressed as a
cladogram typical for
cladistics
Taxonomy (biology)
–
Type specimen for
Nepenthes smilesii, a tropical
pitcher plant.
6.
Animal
–
Animals are multicellular, eukaryotic organisms of the kingdom Animalia. The animal kingdom emerged as a clade within Apoikozoa as the group to the choanoflagellates. Animals are motile, meaning they can move spontaneously and independently at some point in their lives and their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later in their lives. All animals are heterotrophs, they must ingest other organisms or their products for sustenance, most known animal phyla appeared in the fossil record as marine species during the Cambrian explosion, about 542 million years ago. Animals can be divided broadly into vertebrates and invertebrates, vertebrates have a backbone or spine, and amount to less than five percent of all described animal species. They include fish, amphibians, reptiles, birds and mammals, the remaining animals are the invertebrates, which lack a backbone. These include molluscs, arthropods, annelids, nematodes, flatworms, cnidarians, ctenophores, the study of animals is called zoology. The word animal comes from the Latin animalis, meaning having breath, the biological definition of the word refers to all members of the kingdom Animalia, encompassing creatures as diverse as sponges, jellyfish, insects, and humans. Aristotle divided the world between animals and plants, and this was followed by Carl Linnaeus, in the first hierarchical classification. In Linnaeuss original scheme, the animals were one of three kingdoms, divided into the classes of Vermes, Insecta, Pisces, Amphibia, Aves, and Mammalia. Since then the last four have all been subsumed into a single phylum, in 1874, Ernst Haeckel divided the animal kingdom into two subkingdoms, Metazoa and Protozoa. The protozoa were later moved to the kingdom Protista, leaving only the metazoa, thus Metazoa is now considered a synonym of Animalia. Animals have several characteristics that set apart from other living things. Animals are eukaryotic and multicellular, which separates them from bacteria and they are heterotrophic, generally digesting food in an internal chamber, which separates them from plants and algae. They are also distinguished from plants, algae, and fungi by lacking cell walls. All animals are motile, if only at life stages. In most animals, embryos pass through a stage, which is a characteristic exclusive to animals. With a few exceptions, most notably the sponges and Placozoa and these include muscles, which are able to contract and control locomotion, and nerve tissues, which send and process signals
Animal
–
Carl Linnaeus, known as the father of modern
taxonomy
Animal
–
Had'n
Animal
–
The use of
love darts by the land snail
Monachoides vicinus is a form of
sexual selection
Animal
–
A
newt lung cell stained with
fluorescent dyes undergoing the early
anaphase stage of
mitosis
7.
Mollusc
–
The molluscs compose the large phylum Mollusca of invertebrate animals. Around 85,000 extant species of molluscs are recognized, molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats and they are highly diverse, not just in size and in anatomical structure, but also in behaviour and in habitat. The phylum is divided into 9 or 10 taxonomic classes. The gastropods are by far the most numerous molluscs in terms of classified species, the three most universal features defining modern molluscs are a mantle with a significant cavity used for breathing and excretion, the presence of a radula, and the structure of the nervous system. Other than these things, molluscs express great morphological diversity, so many textbooks base their descriptions on an ancestral mollusc. This has a single, limpet-like shell on top, which is made of proteins and chitin reinforced with calcium carbonate, the underside of the animal consists of a single muscular foot. Although molluscs are coelomates, the coelom tends to be small, the main body cavity is a hemocoel through which blood circulates, their circulatory systems are mainly open. The generalized mollusc has two paired nerve cords, or three in bivalves, the brain, in species that have one, encircles the esophagus. Most molluscs have eyes, and all have sensors to detect chemicals, vibrations, the simplest type of molluscan reproductive system relies on external fertilization, but more complex variations occur. All produce eggs, from which may emerge trochophore larvae, more complex veliger larvae, good evidence exists for the appearance of gastropods, cephalopods and bivalves in the Cambrian period 541 to 485.4 million years ago. Molluscs have, for centuries, also been the source of important luxury goods, notably pearls, mother of pearl, Tyrian purple dye and their shells have also been used as money in some preindustrial societies. Mollusc species can also represent hazards or pests for human activities, the bite of the blue-ringed octopus is often fatal, and that of Octopus apollyon causes inflammation that can last for over a month. Stings from a few species of large tropical cone shells can also kill, schistosomiasis is transmitted to humans via water snail hosts, and affects about 200 million people. Snails and slugs can also be serious pests, and accidental or deliberate introduction of some snail species into new environments has seriously damaged some ecosystems. The words mollusc and mollusk are both derived from the French mollusque, which originated from the Latin molluscus, from mollis, molluscus was itself an adaptation of Aristotles τα μαλακά, the soft things, which he applied to cuttlefish. The scientific study of molluscs is accordingly called malacology, as it is now known these groups have no relation to molluscs, and very little to one another, the name Molluscoida has been abandoned. The most universal features of the structure of molluscs are a mantle with a significant cavity used for breathing and excretion
Mollusc
Mollusc
–
Cornu aspersum (formerly Helix aspersa) – a common land
snail
Mollusc
–
About 80% of all known mollusc species are
gastropods (
snails and
slugs), including this
cowry (a sea snail).
Mollusc
–
The use of
love darts by the land snail
Monachoides vicinus is a form of
sexual selection
8.
Gastropod
–
The Gastropoda or gastropods, more commonly known as snails and slugs, are a large taxonomic class within the phylum Mollusca. The class Gastropoda includes snails and slugs of all kinds and all sizes from microscopic to large, there are many thousands of species of sea snails and sea slugs, as well as freshwater snails, freshwater limpets, land snails and land slugs. The class Gastropoda contains a vast total of named species, second only to the insects in overall number, the fossil history of this class goes back to the Late Cambrian. There are 611 families of known, of which 202 are extinct. Gastropoda are a part of the phylum Mollusca, and are the most highly diversified class in the phylum, with 65,000 to 80,000 living snail. The anatomy, behavior, feeding, and reproductive adaptations of gastropods vary significantly from one clade or group to another, therefore, it is difficult to state many generalities for all gastropods. The class Gastropoda has an extraordinary diversification of habitats and those gastropods without a shell, and those with only a very reduced or internal shell, are usually known as slugs, those with a shell into which they cannot withdraw are termed limpets. In a number of families of species, such as all the various limpets, the shell is coiled only in the larval stage, in the scientific literature, gastropods were described under gasteropodes by Georges Cuvier in 1795. Cuvier chose gastropod by derivation from the Ancient Greek words γαστήρ stomach, the earlier name univalve means one valve or shell, in contrast to bivalve applied to mollusks such as clams and meaning that those animals possess two valves or shells. At all taxonomic levels, gastropods are second only to the insects in terms of their diversity, Gastropods have the greatest numbers of named mollusc species. However, estimates of the number of gastropod species vary widely. The number of species can be ascertained from estimates of the number of described species of Mollusca with accepted names. But an estimate of the number of Mollusca, including undescribed species, is about 240,000 species. The estimate of 85,000 molluscs includes 24,000 described species of terrestrial gastropods, different estimates for aquatic gastropods give about 30,000 species of marine gastropods, and about 5,000 species of freshwater and brackish gastropods. The total number of living species of snails is about 4,000. There are 444 recently extinct species of gastropods,18 species that are now extinct in the wild and 69 possibly extinct species, the number of prehistoric species of gastropods is at least 15,000 species. Some of the familiar and better-known gastropods are terrestrial gastropods and some live in freshwater. Gastropods have a distribution from the near Arctic and Antarctic zones to the tropics
Gastropod
Gastropod
–
The upper pair of
tentacles on the head of Helix pomatia have eye spots, but the main sensory organs of the snail are sensory receptors for
olfaction, situated in the
epithelium of the tentacles.
Gastropod
–
A 9-hour-old
trochophore of
Haliotis asinina sf -
shell field
9.
Calcareous
–
Calcareous is an adjective meaning mostly or partly composed of calcium carbonate, in other words, containing lime or being chalky. The term is used in a variety of scientific disciplines. The term also applies to the calcium carbonate tests of often more or less microscopic Foraminifera, note that not all tests are calcareous, diatoms and radiolaria have siliceous tests. The molluscs are calcareous, as are calcareous sponges, that have spicules which are made of calcium carbonate, calcareous grassland is a form of grassland characteristic of soils containing much calcium carbonate from underlying chalk or limestone rock. Species of algae such as the green-segmented genus Halimeda are calcareous, the term is used in pathology, for example in calcareous conjunctivitis, and when referring to calcareous metastasis or calcareous deposits, which may both be removed surgically. The term calcareous can be applied to a sediment, sedimentary rock, or soil type which is formed from, or contains a proportion of. Calcareous sediments are deposited in shallow water near land, since the carbonate is precipitated by marine organisms that need land-derived nutrients. Generally speaking, the farther from land sediments fall, the less calcareous they are, some areas can have interbedded calcareous sediments due to storms, or changes in ocean currents. Calcareous ooze is a form of calcium derived from planktonic organisms that accumulates on the sea floor. This can only occur if the ocean is shallower than the carbonate compensation depth, below this depth, calcium carbonate begins to dissolve in the ocean, and only non-calcareous sediments are stable, such as siliceous ooze or pelagic red clay. Calcareous soils are alkaline, in other words they have a high pH. This is because of the very weak acidity of carbonic acid, note that this is not the only reason for a high soil pH
Calcareous
–
Calcareous
sandstone in
Seven Sisters Country Park
Calcareous
–
Calcareous mine in
Perm Krai,
Russia
10.
Epiphragm
–
An epiphragm is a temporary structure which can be created by many species of shelled, air-breathing land snails, terrestrial pulmonate gastropod mollusks. It can also be created by freshwater snails when temporary pools dry up, in most species the epiphragm is made of dried mucus, and although it is elastic, it is fairly easily torn when forcibly removing a snail from its substrate. In a few species the epiphragm is thick and quite rigid and this kind of epiphragm is very strong and may be difficult to break. The epiphragm is created to seal the aperture of the shell against desiccation and it is used when the snail is inactive. Most land snails are active when the humidity is high such as after rain and at night. The main function of the epiphragm is to water loss through the aperture during inactivity. An operculum is a similar but permanent anatomical feature that is found in other clades of gastropods. The operculum serves some of the functions as an epiphragm. Sometimes it protects the snail against predation and it protects certain species of snail if they are eaten by birds. The snail can remain alive as it passes through the digestive tract because it is protected from the digestive enzymes, snails may also benefit from being moved to new locations. In most species of air-breathing land snail, the epiphragm is a membrane composed of layers of dried mucus. This is created routinely at the start of a period of inactivity during times of decreased humidity, the epiphragm of Helix aspersa is secreted from the mantle collar of the snail by intense muscular activity. A mucus epiphragm is usually transparent or translucent, and is fairly elastic, a few species, including Helix pomatia create a normal mucus epiphragm for short periods of rest, but can also create a different, specialized solid hard epiphragm, prior to annual hibernation. This kind of epiphragm is a structure composed mainly of calcium carbonate. This specialized epiphragm is much more efficient at conserving water loss than a thin mucus epiphragm would be and this very sturdy flat calcareous structure has a small perforation to allow for oxygen exchange
Epiphragm
–
Helix pomatia using a simple transparent epiphragm made of dried mucus
Epiphragm
–
A hibernating
Helix pomatia with a
calcareous epiphragm in place
Epiphragm
–
The calcareous epiphragm of Helix pomatia: view of the inner surface, left, and the outer surface, right
Epiphragm
–
Helix lutescens with a calcareous epiphragm in place
11.
Land snails
–
A land snail is any of the numerous species of snail that live on land, as opposed to sea snails and freshwater snails. Land snail is the name for terrestrial gastropod mollusks that have shells. The majority of land snails are pulmonates and that is, they have a lung and breathe air. A minority however belong to more ancient lineages where their anatomy includes a gill. Many of these land snails live in habitats or microhabitats that are sometimes damp or wet. Land snails have a muscular foot, they use mucus to enable them to crawl over rough surfaces. Like other mollusks, land snails have a mantle, and they have one or two pairs of tentacles on their head and their internal anatomy includes a radula and a primitive brain. In terms of reproduction, the majority of land snails are hermaphrodite, tiny snails hatch out of the egg with a small shell in place, and the shell grows spirally as the soft parts gradually increase in size. Most land snails have shells that are right-handed in their coiling, Land snails move by gliding along on their muscular foot, which is lubricated with mucus and covered with epithelial cilia. This motion is powered by succeeding waves of contractions that move down the ventral of the foot. This muscular action is visible when a snail is crawling on the glass of a window or aquarium. Snails move at a low speed. Snails secrete mucus externally to keep their bodies from drying out. The mucus that land snails secrete with the leaves a slime trail behind them. Snails also have a mantle, a layer of tissue which covers all of the internal organs as they are grouped together in the visceral mass. The mantle also extends outward in flaps which reach to the edge of the shell and in some cases can cover the shell, the mantle is attached to the shell, and creates the shell and makes shell growth possible by secretion. A lack of calcium, or low pH in their surroundings, can result in thin, cracked, usually a snail can repair damage to its shell over time if its living conditions improve, but severe damage can be fatal. When retracted into their shells, many snails with gills are able to protect themselves with a door-like anatomical structure called an operculum, Land snails range greatly in size
Land snails
–
Helix pomatia, a species of air-breathing land snail
Land snails
–
Colonies of snails in Sicily.
Land snails
–
Cornu Aspersum (previously known as
Helix Aspersa) – the common garden snail
Land snails
–
The Teeth of a Snail from
Robert Hooke 's
Micrographia, 1665
12.
Pulmonate
–
Pulmonata, or pulmonates, is an informal group of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group includes many land and freshwater families, and several marine families, the taxon Pulmonata as traditionally defined was found to be polyphyletic in a molecular study per Jörger et al. dating from 2010. Pulmonata are known from the Carboniferous Period to the present, pulmonates have a single atrium and kidney, and a concentrated, symmetrical, nervous system. The mantle cavity is located on the side of the body. Most species have a shell, but no operculum, although the group also include several shell-less slugs. Pulmonates are hermaphroditic, and some groups possess love darts, & A. E. Gray,1806 Superfamily Strophocheiloidea Thiele,1926 Superfamily Trigonochlamydoidea Hese,1882 Superfamily Zonitoidea Mörch,1864. Superfamily Athoracophoroidea P. Fischer,1883 = Tracheopulmonata and they proposed the more inclusive taxon Panpulmonata to unite the clades Siphonarioidea, Sacoglossa, Glacidorboidea, Pyramidelloidea, Amphiboloidea, Hygrophila, Acochlidia and Eupulmonata. Wade, C. M. Mordan, P. B, a phylogeny of the land snails. Proceedings of the Royal Society B, Biological Sciences, holznagel, W. E. Colgan, D. J. Lydeard, C. Pulmonate phylogeny based on 28S rRNA gene sequences, A framework for discussing habitat transitions, pulmonate snails & slugs in captivity
Pulmonate
Pulmonate
–
Shells of pulmonate styllomatophoran snails in a museum collection
Pulmonate
–
An artistic but scientifically incorrect version of various European land snails and slugs (one species here is not a pulmonate), their food plants and fungi, and a beetle that eats mollusks, bottom right.
Pulmonate
–
Examples of Pulmonata:
Achatina fulica top right,
Bielzia coerulans top left,
Praticolella berlandieriana center right,
Megalobulimus oblongus in the center,
Euglandina rosea center left, Helix pomatia bottom right &
Ashmunella levettei bottom left
13.
Gastropoda
–
The Gastropoda or gastropods, more commonly known as snails and slugs, are a large taxonomic class within the phylum Mollusca. The class Gastropoda includes snails and slugs of all kinds and all sizes from microscopic to large, there are many thousands of species of sea snails and sea slugs, as well as freshwater snails, freshwater limpets, land snails and land slugs. The class Gastropoda contains a vast total of named species, second only to the insects in overall number, the fossil history of this class goes back to the Late Cambrian. There are 611 families of known, of which 202 are extinct. Gastropoda are a part of the phylum Mollusca, and are the most highly diversified class in the phylum, with 65,000 to 80,000 living snail. The anatomy, behavior, feeding, and reproductive adaptations of gastropods vary significantly from one clade or group to another, therefore, it is difficult to state many generalities for all gastropods. The class Gastropoda has an extraordinary diversification of habitats and those gastropods without a shell, and those with only a very reduced or internal shell, are usually known as slugs, those with a shell into which they cannot withdraw are termed limpets. In a number of families of species, such as all the various limpets, the shell is coiled only in the larval stage, in the scientific literature, gastropods were described under gasteropodes by Georges Cuvier in 1795. Cuvier chose gastropod by derivation from the Ancient Greek words γαστήρ stomach, the earlier name univalve means one valve or shell, in contrast to bivalve applied to mollusks such as clams and meaning that those animals possess two valves or shells. At all taxonomic levels, gastropods are second only to the insects in terms of their diversity, Gastropods have the greatest numbers of named mollusc species. However, estimates of the number of gastropod species vary widely. The number of species can be ascertained from estimates of the number of described species of Mollusca with accepted names. But an estimate of the number of Mollusca, including undescribed species, is about 240,000 species. The estimate of 85,000 molluscs includes 24,000 described species of terrestrial gastropods, different estimates for aquatic gastropods give about 30,000 species of marine gastropods, and about 5,000 species of freshwater and brackish gastropods. The total number of living species of snails is about 4,000. There are 444 recently extinct species of gastropods,18 species that are now extinct in the wild and 69 possibly extinct species, the number of prehistoric species of gastropods is at least 15,000 species. Some of the familiar and better-known gastropods are terrestrial gastropods and some live in freshwater. Gastropods have a distribution from the near Arctic and Antarctic zones to the tropics
Gastropoda
Gastropoda
–
The upper pair of
tentacles on the head of Helix pomatia have eye spots, but the main sensory organs of the snail are sensory receptors for
olfaction, situated in the
epithelium of the tentacles.
Gastropoda
–
A 9-hour-old
trochophore of
Haliotis asinina sf -
shell field
14.
Gastropod shell
–
The gastropod shell is part of the body of a gastropod or snail, a kind of mollusk or mollusc. The shell is a skeleton or exoskeleton, which may serve for muscle attachment, but also for protection from predators, mechanical damage, dehydration. Some gastropods appear shell-less but may have a remnant within the mantle, some snails also possess an operculum that seals the opening of the shell, known as the aperture, which provides further protection. The study of shells is known as conchology. The biological study of gastropods, and other molluscs in general, is malacology, Shell morphology terms vary by species group. An excellent source for terminology of the shell is How to Know the Eastern Land Snails by John B. Burch now freely available at the Hathi Trust Digital Library, the gastropod shell has three major layers secreted by the mantle. The calcareous central layer, the ostracum, is made of calcium carbonate precipitated into an organic matrix known as conchiolin. The outermost layer is the periostracum which is resistant to abrasion, gastropod shell morphology is usually quite constant among individuals of a species. Controlling variables are, The rate of growth per revolution around the coiling axis, high rates give wide-mouthed forms such as the abalone, low rates give highly coiled forms such as Turritella or some of the Planorbidae. The shape of the curve, roughly equivalent to the shape of the aperture. It may be round, for instance in the shell, elongate as in the cone shell or have an irregular shape with a siphonal canal extension. The rate of translation of the curve along the axis of coiling, controlling how high-spired the resulting shell becomes. This may range from zero, a flat shell, to nearly the diameter of the aperture. Ontologic growth changes as the animal reaches adulthood, good examples are the flaring lip of the adult conch and the inward-coiled lip of the cowry. Some of these factors can be modelled mathematically and programs exist to generate extremely realistic images, early work by David Raup on the analog computer also revealed many possible combinations that were never adopted by any actual gastropod. Some shell shapes are more often in certain environments, though there are many exceptions. High-spired and highly sculptured forms become more common in water environments
Gastropod shell
–
Shells of two different species of sea snail: on the left is the normally sinistral (left-handed) shell of
Neptunea angulata, on the right is the normally dextral (right-handed) shell of
Neptunea despecta
Gastropod shell
–
The shell of a large land snail (probably
Helix pomatia) with parts broken off to show the interior structure. 1 –
umbilicus 2 –
columellar plait 3 –
aperture 4 –
columella 5 –
suture 6 – body whorl 7 – apex
Gastropod shell
–
Four views of a shell of
Arianta arbustorum: Apertural view of (top left), lateral view (top right), apical view (bottom left), and umbilical view (bottom right).
Gastropod shell
15.
Freshwater snail
–
Freshwater snails are gastropod mollusks which live in freshwater. They are found throughout the world in various habitats, ranging from ephemeral pools to the largest lakes, the great majority of freshwater gastropods have a shell, with very few exceptions. Some groups of snails that live in freshwater respire using gills, most feed on algae, but many are detritivors and some are filter feeders. According to a 2008 review of the taxonomy, there are about 4,000 species of freshwater gastropods, at least 33–38 independent lineages of gastropods have successfully colonized freshwater environments. It is not possible to quantify the number of these lineages yet. From six to eight of these independent lineages occur in North America, and simplified with families that contain freshwater species marked in boldface, The Neritimorpha are a group of primitive prosobranch gilled snails which have a shelly operculum. Neritiliidae,5 extant freshwater species Neritidae, largely confined to the tropics, also the rivers of Europe, there are about 110 extant freshwater species. The Caenogastropoda are a group of gilled operculate snails, which are largely marine. Viviparidae, medium to large snails, live-bearing, commonly referred to as mystery snails, worldwide except South America, and everywhere confined to fresh waters. Sorbeoconcha Melanopsidae, family native to rivers draining to the Mediterranean, also Middle East, native to South and Central America. Formerly included with the Pleuroceridae by many authors, paludomidae - about 100 species in south Asia, diverse in African Lakes, and Sri Lanka. Formerly classified with the Pleuroceridae by some authors, Pleuroceridae, abundant and diverse in eastern North America, largely high-spired snails of small to large size. Semisulcospiridae, - primarily eastern Asia, Japan, also the Juga snails of northwestern North America, thiaridae, high-spired parthenogenic snails of the tropics, includes those referred to as trumpet snails in aquaria. Littorinimorpha Littorinidae -9 species in the genus Cremnoconchus are freshwater living in streams, assimineidae - about 20 freshwater species, other are marine Bithyniidae, small snails, native to Eastern Hemisphere. Helicostoidae, the only species Helicostoa sinensis lives in China, hydrobiidae, small to very small snails found worldwide. About 1250 freshwater species other are marine, Pomatiopsidae, small amphibious snails scattered worldwide, most diverse in eastern and Southeast Asia. Stenothyridae - about 60 freshwater species, others are marine, neogastropoda Buccinidae - 8-10 freshwater species in the genus Clea, native to Southeast Asia. Marginellidae -2 freshwater species in the genus Rivomarginella, native to Southeast Asia, lower Heterobranchia Glacidorbidae -20 species
Freshwater snail
–
Bithynia tentaculata, a small freshwater gastropod in the family
Bithyniidae
Freshwater snail
–
Pomacea insularum, an apple snail
Freshwater snail
–
Planorbella trivolvis, an air-breathing ramshorn snail
Freshwater snail
–
Family
Neritidae, shells of
Theodoxus fluviatilis.
16.
Semi-slug
–
Semi-slugs, also spelled semislugs, are land gastropods whose shells are too small for them to retract into, but not quite vestigial. The shell of some semi-slugs may not be visible on casual inspection. This is a type of gastropod that is intermediate between a slug and a land snail, there exist a number of gastropod families that have semi-slugs species. There exist about 1000 species of semi-slugs in comparison to about only 500 species of slugs
Semi-slug
–
Drawing of two views of
Cryptella canariensis from the
Canary Islands
Semi-slug
–
An unidentified semi-slug from
Uganda
17.
Natica chemnitzi
–
Neverita didyma, common name the bladder moon snail, is a species of predatory sea snail, a marine gastropod mollusk in the family Naticidae, the moon snails. Neverita didyma ampla Neverita didyma hayashii Neverita didyma hosoyai The size of a shell of this species varies between 20 mm and 90 mm. Like all naticids, this species is a carnivore and a predator and this marine species is found in the Indian Ocean off the coasts of Madagascar, Mozambique and South Africa. Dautzenberg, Ph. Mollusques testacés marins de Madagascar, faune des Colonies Francaises, Tome III MacNae, W. & M. Kalk. A natural history of Inhaca Island, Mozambique, i-iv,163 pp. Branch, G. M. et al. David Philip, Cate Town & Johannesburg Kilburn, R. N, macmillan South Africa, Johannesburg, xi +249 pp. page,71 Steyn, D. G. & Lussi, M. Marine Shells of South Africa, an Illustrated Collector’s Guide to Beached Shells. Ekogilde Publishers, Hartebeespoort, South Africa, ii +264 pp. page,50 Hollman M. Naticidae, revision on the classification of Recent Naticidae. Bulletin of the Nishinomiya Shell Museum 7,133 +15 pp.4 pls Gastropods. com, Polinices didyma, accessed,14 April 2011 Polinices didyma
Natica chemnitzi
–
Neverita didyma
Natica chemnitzi
–
Egg mass
18.
Cerithium
–
Cerithium is a genus of small to medium-sized sea snails, marine gastropod mollusks in the family Cerithiidae, the ceriths. Species within this genus include, The genus is known from the Triassic to the Recent periods, fossils shells have been found all over the world. C. A classification of the living Mollusca, monograph of the genus Cerithium Bruguière in the Indo-Pacific. Smithsonian contributions to Zoology 510, 1-211 Petuch E.2001, new Gastropods named for Frederick M. Bayer, in Recognition of his Contributions to Tropical Western Atlantic Malacology. Bulletin of the Biological Society of Washington 10, 334-343 Gofas, le Renard, J. Bouchet, P. Mollusca, in, Costello, M. J. et al. European register of marine species, a check-list of the species in Europe. Collection Patrimoines Naturels,50, pp. 180–213
Cerithium
Cerithium
–
Fossil shells of Cerithium crenatum from Pliocene of Italy
Cerithium
–
Cerithium caeruleum
Cerithium
–
Cerithium columna
19.
Gulf of California
–
The Gulf of California is a body of water that separates the Baja California Peninsula from the Mexican mainland. It is bordered by the states of Baja California, Baja California Sur, Sonora, rivers which flow into the Gulf of California include the Colorado, Fuerte, Mayo, Sinaloa, Sonora, and the Yaqui. The gulfs surface area is about 160,000 km2, the Gulf is thought to be one of the most diverse seas on the planet, and is home to more than 5,000 species of micro-invertebrates. Home to over a people, Baja California is one of the longest peninsulas in the world. Parts of the Gulf of California are a UNESCO World Heritage Site, the International Hydrographic Organization defines the southern limit of the Gulf of California as, A line joining Piastla Point in Mexico, and the southern extreme of Lower California. The Gulf of California is 1,126 km long and 48–241 km wide, with an area of 177,000 km2, a depth of 818.08 m. Transition zones exist between regions, and they usually vary for each individual species. The temperature of the water in the Gulf of California generally experiences lows of 16 °C in winter, but temperatures can vary greatly in the gulf, and the water is almost always warmer by the coast than the open ocean. For example, the waters surrounding La Paz reach 30 °C in August, while the waters in neighboring city Cabo San Lucas, occasionally, the northern Gulf of California will go through significantly cold winters. The water in the Northern Gulf can sometimes drop below 8 °C, the animals most susceptible to the large decrease in water temperature include macroscopic algae and plankton. As part of process, the East Pacific Rise propagated up the middle of the Gulf along the seabed. This extension of the East Pacific Rise is often referred to as the Gulf of California Rift Zone, the Gulf would extend as far as Indio, California, except for the tremendous delta created by the Colorado River. This delta blocks the sea from flooding the Mexicali and Imperial Valleys, volcanism dominates the East Pacific Rise. The island of Isla Tortuga is one example of ongoing volcanic activity. Furthermore, hydrothermal vents due to extension tectonic regime, related to the opening of the Gulf of California, are found in the Bahía de Concepción, the narrow sea is home to a unique and rich ecosystem. The unusual resident populations of fin whales and sperm whales do not migrate annually, the area near the delta of the Colorado river has a small remnant population of the totoaba fish. This region has historically been a magnet for world-class sport fishing activities, the region also has a rich history as a commercial fishery. However, the data vary wildly according to the species being studied, moreover, changes in terrestrial ecology, such as the vast reduction in flow from the Colorado River into the Gulf, have negatively affected fisheries, particularly in the northern region
Gulf of California
–
The Gulf of California (highlighted)
Gulf of California
–
Satellite picture of gulf.
Gulf of California
–
Giant Pacific
manta ray
Gulf of California
20.
Pulmonata
–
Pulmonata, or pulmonates, is an informal group of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group includes many land and freshwater families, and several marine families, the taxon Pulmonata as traditionally defined was found to be polyphyletic in a molecular study per Jörger et al. dating from 2010. Pulmonata are known from the Carboniferous Period to the present, pulmonates have a single atrium and kidney, and a concentrated, symmetrical, nervous system. The mantle cavity is located on the side of the body. Most species have a shell, but no operculum, although the group also include several shell-less slugs. Pulmonates are hermaphroditic, and some groups possess love darts, & A. E. Gray,1806 Superfamily Strophocheiloidea Thiele,1926 Superfamily Trigonochlamydoidea Hese,1882 Superfamily Zonitoidea Mörch,1864. Superfamily Athoracophoroidea P. Fischer,1883 = Tracheopulmonata and they proposed the more inclusive taxon Panpulmonata to unite the clades Siphonarioidea, Sacoglossa, Glacidorboidea, Pyramidelloidea, Amphiboloidea, Hygrophila, Acochlidia and Eupulmonata. Wade, C. M. Mordan, P. B, a phylogeny of the land snails. Proceedings of the Royal Society B, Biological Sciences, holznagel, W. E. Colgan, D. J. Lydeard, C. Pulmonate phylogeny based on 28S rRNA gene sequences, A framework for discussing habitat transitions, pulmonate snails & slugs in captivity
Pulmonata
Pulmonata
–
Shells of pulmonate styllomatophoran snails in a museum collection
Pulmonata
–
An artistic but scientifically incorrect version of various European land snails and slugs (one species here is not a pulmonate), their food plants and fungi, and a beetle that eats mollusks, bottom right.
Pulmonata
–
Examples of Pulmonata:
Achatina fulica top right,
Bielzia coerulans top left,
Praticolella berlandieriana center right,
Megalobulimus oblongus in the center,
Euglandina rosea center left, Helix pomatia bottom right &
Ashmunella levettei bottom left
21.
Polyphyletic
–
A polyphyletic group is characterized by one or more homoplasies, phenotypes which have converged or reverted so as to appear to be the same but which have not been inherited from common ancestors. Alternatively, polyphyletic is used to describe multiple ancestral sources regardless of convergence, for example, warm-bloodedness evolved separately in the ancestors of mammals and the ancestors of birds. Other polyphyletic groups are protozoans, lipotyphla, and algae, as well as invertebrates, many biologists aim to avoid homoplasies in grouping species together and therefore it is frequently a goal to eliminate groups that are found to be polyphyletic. This is often the stimulus for major revisions of the classification schemes, in many schools of taxonomy, the existence of polyphyletic groups in a classification is discouraged. Monophyletic groups are considered by these schools of thought to be the most important grouping of organisms, on the other hand, polyphyletic groups can often be delimited in terms of clades, for example the flying vertebrates consist of the bat, bird, and pterosaur clades. Because polyphyletic groups can frequently be defined as a sum of clades, a stronger reason is that grouping species monophyletically facilitates prediction far more than does polyphyletic grouping. Predictive success is the touchstone by which theories are evaluated in all experimental sciences, species have a special status in systematics as being an observable feature of nature itself and as the basic unit of classification. It is usually assumed that species are monophyletic. However hybrid speciation arguably leads to polyphyletic species, hybrid species are a common phenomenon in nature, particularly in plants where polyploidy allows for rapid speciation. Funk, D. J. and Omland, K. E. Species-level paraphyly and polyphyly, Frequency, cause and consequences, with insights from animal mitochondrial DNA Annu
Polyphyletic
–
Cladogram of the
primates, showing a
monophyly (the simians, in yellow), a
paraphyly (the prosimians, in blue, including the red patch), and a polyphyly (the night-active primates, the
lorises and the
tarsiers, in red).
22.
Gill
–
A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water and excretes carbon dioxide. The gills of species, such as hermit crabs, have adapted to allow respiration on land provided they are kept moist. The microscopic structure of a gill presents a surface area to the external environment. Many microscopic aquatic animals, and some larger but inactive ones, can absorb oxygen through the entire surface of their bodies. However, more complex or more active aquatic organisms usually require a gill or gills, Gills usually consist of thin filaments of tissue, branches, or slender, tufted processes that have a highly folded surface to increase surface area. A high surface area is crucial to the gas exchange of aquatic organisms, a cubic meter of air contains about 250 grams of oxygen at STP. The concentration of oxygen in water is lower than in air, in fresh water, the dissolved oxygen content is approximately 8 cm3/L compared to that of air which is 210 cm3/L. Water is 777 times more dense than air and is 100 times more viscous, oxygen has a diffusion rate in air 10,000 times greater than in water. The use of sac-like lungs to remove oxygen from water would not be efficient enough to sustain life, rather than using lungs, aseous exchange takes place across the surface of highly vascularised gills over which a one-way current of water is kept flowing by a specialised pumping mechanism. The density of the water prevents the gills from collapsing and lying on top of each other, with the exception of some aquatic insects, the filaments and lamellae contain blood or coelomic fluid, from which gases are exchanged through the thin walls. The blood carries oxygen to other parts of the body, carbon dioxide passes from the blood through the thin gill tissue into the water. Gills or gill-like organs, located in different parts of the body, are found in groups of aquatic animals, including mollusks, crustaceans, insects, fish. The gills of vertebrates typically develop in the walls of the pharynx, most species employ a countercurrent exchange system to enhance the diffusion of substances in and out of the gill, with blood and water flowing in opposite directions to each other. The gills are composed of filaments, the gill lamellae. When a fish breathes, it draws in a mouthful of water at regular intervals, then it draws the sides of its throat together, forcing the water through the gill openings, so it passes over the gills to the outside. Fish gill slits may be the ancestors of the tonsils, thymus glands. Adjacent slits are separated by a gill arch from which projects a cartilaginous gill ray. This gill ray is the support for the sheet-like interbranchial septum, the base of the arch may also support gill rakers, projections into the pharyngeal cavity that help to prevent large pieces of debris from damaging the delicate gills
Gill
–
The red gills of this
common carp are visible as a result of a
gill flap birth defect.
Gill
–
Freshwater Fish Gills magnified 400 times
Gill
–
The red gills inside a detached
tuna head (viewed from behind)
Gill
–
An
Alpine newt larva showing the
external gills, which flare just behind the head
23.
Ditch
–
A ditch is a small to moderate depression created to channel water. A ditch can be used for drainage, to water from low-lying areas, alongside roadways or fields. A trench is a narrow ditch. Ditches are commonly seen around farmland, especially in areas that have required drainage, such as The Fens in eastern England and much of the Netherlands. Roadside ditches may provide a hazard to motorists and cyclists, whose vehicles may crash into them and get damaged, flipped over or stuck, especially in weather conditions. In Anglo-Saxon, the word dïc already existed and was pronounced deek in northern England, the origins of the word lie in digging a trench and forming the upcast soil into a bank alongside it. This practice has meant that the name dïc was given to either the excavation or the bank, thus Offas Dyke is a combined structure and Car Dyke is a trench, though it once had raised banks as well. In the midlands and north of England, a dike is what a ditch is in the south, a property boundary marker or small drainage channel. Where it carries a stream, it may be called a dike as in Rippingale Running Dike. The Weir Dike is a dike in Bourne North Fen, near Twenty. Drainage ditches play major roles in agriculture throughout the world, improper drainage systems accelerate water contamination, excessively desiccate soils during seasonal drought, and become a financial burden to maintain. Industrial earth-moving equipment facilitates maintenance of straight drainage trenches, but entrenchment results in increasing environmental, sustainable channel design can result in ditches that are largely self-maintaining due to natural geomorphological equilibrium. Slowed net siltation and erosion result in net reduction in sediment transport, flooding can be a major cause of recurring crop loss—particularly in heavy soils—and can severely disrupt urban economies as well. However, excess drainage results in recurring drought induced crop yield losses, controlled subsurface drainage from sensitive areas to vegetated drainage ditches makes possible a better balance between water drainage and water retention needs. The initial investment allows a community to draw down local water tables when, particularly in Colorado, the term ditch is also applied to open aqueducts that traverse hillsides as part of transbasin diversion projects. Examples include the Grand Ditch over La Poudre Pass, the Berthoud Pass Ditch, black Beach, The Mucklands of Canastota, New York
Ditch
–
A well maintained ditch in the Netherlands
Ditch
–
Ditches at the
Ouse Washes nature reserve.
Ditch
–
Waterplants growing in a ditch in the Netherlands, showing
Sagittaria sagittifolia to the right.
24.
Desert
–
A desert is a barren area of land where little precipitation occurs and consequently living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to the processes of denudation, about one third of the land surface of the world is arid or semi-arid. This includes much of the regions where little precipitation occurs. Deserts can be classified by the amount of precipitation falls, by the temperature that prevails. Deserts are formed by weathering processes as large variations in temperature between day and night put strains on the rocks which consequently break in pieces, although rain seldom occurs in deserts, there are occasional downpours that can result in flash floods. Rain falling on hot rocks can cause them to shatter and the resulting fragments and this picks up particles of sand and dust and wafts them aloft in sand or dust storms. Wind-blown sand grains striking any solid object in their path can abrade the surface, rocks are smoothed down, and the wind sorts sand into uniform deposits. The grains end up as level sheets of sand or are piled high in billowing sand dunes, other deserts are flat, stony plains where all the fine material has been blown away and the surface consists of a mosaic of smooth stones. These areas are known as desert pavements and little further erosion takes place, other desert features include rock outcrops, exposed bedrock and clays once deposited by flowing water. Temporary lakes may form and salt pans may be left when waters evaporate, there may be underground sources of water in the form of springs and seepages from aquifers. Where these are found, oases can occur, plants and animals living in the desert need special adaptations to survive in the harsh environment. Plants tend to be tough and wiry with small or no leaves, water-resistant cuticles, some annual plants germinate, bloom and die in the course of a few weeks after rainfall while other long-lived plants survive for years and have deep root systems able to tap underground moisture. Animals need to cool and find enough food and water to survive. Many are nocturnal and stay in the shade or underground during the heat of the day and they tend to be efficient at conserving water, extracting most of their needs from their food and concentrating their urine. Some animals remain in a state of dormancy for long periods and they then reproduce rapidly while conditions are favorable before returning to dormancy. People have struggled to live in deserts and the surrounding lands for millennia. Nomads have moved their flocks and herds to wherever grazing is available, the cultivation of semi-arid regions encourages erosion of soil and is one of the causes of increased desertification. Many trade routes have been forged across deserts, especially across the Sahara Desert, large numbers of slaves were also taken northwards across the Sahara
Desert
–
Valle de la Luna (« Valley of the Moon ») in the
Atacama Desert of
Chile, the world's driest hot desert
Desert
–
Sand dunes in the
Rub' al Khali ("Empty quarter") of
Saudi Arabia
Desert
–
Cold desert: snow surface at Dome C Station, Antarctica
Desert
–
The
Agasthiyamalai hills cut off
Tirunelveli in
India from the
monsoons, creating a
rainshadow region.
25.
Abyssal zone
–
The abyssal zone or abyssopelagic is a layer of the pelagic zone of the ocean. Abyss derives from the Greek word ἄβυσσος, meaning bottomless, at depths of 4,000 to 6,000 metres, this zone remains in perpetual darkness and never receives daylight. These regions are characterised by continuous cold and lack of nutrients. The abyssal zone has temperatures around 2 °C to 3 °C through the large majority of its mass. It is the part of the midnight zone which starts in the bathypelagic waters above. The area below the zone is the sparsely inhabited hadal zone. The zone above is the bathyal zone, the deep trenches or fissures that plunge down thousands of metres below the ocean floor are almost unexplored. Previously, only the bathyscaphe Trieste, the remote control submarine Kaiko, however, as of March 25,2012 one vehicle, the Deepsea Challenger was able to penetrate to a depth of 10,898.4 metres. Abyssal plain Deep sea Mariana Trench
Abyssal zone
–
Layers of the pelagic zone
26.
Terrestrial ecoregion
–
An ecoregion is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than an ecozone. All three of these are less or greater than an ecosystem. Ecoregions cover relatively large areas of land or water, and contain characteristic, the biodiversity of flora, fauna and ecosystems that characterise an ecoregion tends to be distinct from that of other ecoregions. Three caveats are appropriate for all bio-geographic mapping approaches, firstly, no single bio-geographic framework is optimal for all taxa. Ecoregions reflect the best compromise for as many taxa as possible, secondly, ecoregion boundaries rarely form abrupt edges, rather, ecotones and mosaic habitats bound them. Thirdly, most ecoregions contain habitats that differ from their assigned biome, biogeographic provinces may originate due to various barriers. Some physical, some climatic and some ocean chemical related, the history of the term is somewhat vague as it was used in many contexts, forest classifications, biome classifications, biogeographic classifications, etc. The concept of ecoregion of Bailey gives more importance to ecological criteria, while the WWF concept gives more importance to biogeography, there is significant, but not absolute, spatial correlation among these characteristics, making the delineation of ecoregions an imperfect science. Such transition zones are called ecotones, Ecoregions can be categorized using an algorithmic approach or a holistic, “weight-of-evidence” approach where the importance of various factors may vary. An example of the approach is Robert Bailey’s work for the U. S. The intended purpose of ecoregion delineation may affect the method used, according to WWF, the boundaries of an ecoregion approximate the original extent of the natural communities prior to any major recent disruptions or changes. WWF has identified 867 terrestrial ecoregions, and approximately 450 freshwater ecoregions across the Earth, the use of the term ecoregion is an outgrowth of a surge of interest in ecosystems and their functioning. In particular, there is awareness of issues relating to spatial scale in the study and it is widely recognized that interlinked ecosystems combine to form a whole that is greater than the sum of its parts. The Global 200 is the list of ecoregions identified by WWF as priorities for conservation, Terrestrial ecoregions are land ecoregions, as distinct from freshwater and marine ecoregions. In this context, terrestrial is used to mean of land, WWF ecologists currently divide the land surface of the Earth into 8 major ecozones containing 867 smaller terrestrial ecoregions. The WWF effort is a synthesis of previous efforts to define. Many consider this classification to be decisive, and some propose these as stable borders for bioregional democracy initiatives. The eight terrestrial ecozones follow the major floral and faunal boundaries, identified by botanists and zoologists, ecozone boundaries generally follow continental boundaries, or major barriers to plant and animal distribution, like the Himalayas and the Sahara
Terrestrial ecoregion
–
A map location of the
Amazon rainforest ecoregions. The yellow line encloses the ecoregions per the World Wide Fund for Nature.
Terrestrial ecoregion
–
A map of North America's Bioregions
Terrestrial ecoregion
–
The
Ötztal Alps, a
mountain range in the central
Alps of
Europe, are part of the
Central Eastern Alps, and can both be termed as ecoregions.
Terrestrial ecoregion
–
A conifer forest in the
Swiss Alps (
National Park).
27.
Marine biology
–
Marine biology is the scientific study of organisms in the sea. Marine biology differs from marine ecology as marine ecology is focused on how organisms interact with each other, a large proportion of all life on Earth lives in the ocean. The exact size of this proportion is unknown, since many ocean species are still to be discovered. The ocean is a complex three-dimensional world covering approximately 71% of the Earths surface, the organisms studied range from microscopic phytoplankton and zooplankton to huge cetaceans 30 meters in length. Marine life is a vast resource, providing food, medicine, at a fundamental level, marine life helps determine the very nature of our planet. Marine organisms contribute significantly to the cycle, and are involved in the regulation of the Earths climate. Shorelines are in part shaped and protected by marine life, many species are economically important to humans, including both finfish and shellfish. It is also becoming understood that the well-being of marine organisms, the human body of knowledge regarding the relationship between life in the sea and important cycles is rapidly growing, with new discoveries being made nearly every day. These cycles include those of matter and of air, large areas beneath the ocean surface still remain effectively unexplored. The study of marine biology dates back to Aristotle, who made observations of life in the sea around Lesbos. In 1768, Samuel Gottlieb Gmelin published the Historia Fucorum, the first work dedicated to marine algae and it included elaborate illustrations of seaweed and marine algae on folded leaves. The British naturalist Edward Forbes is generally regarded as the founder of the science of marine biology, the pace of oceanographic and marine biology studies quickly accelerated during the course of the 19th century. The observations made in the first studies of marine biology fueled the age of discovery, during this time, a vast amount of knowledge was gained about the life that exists in the oceans of the world. Many voyages contributed significantly to this pool of knowledge, among the most significant were the voyages of the HMS Beagle where Charles Darwin came up with his theories of evolution and on the formation of coral reefs. The creation of laboratories was important because it allowed marine biologists to conduct research. The oldest marine laboratory in the world, Station biologique de Roscoff, was established in France in 1872, in the United States, the Scripps Institution of Oceanography dates back to 1903, while the prominent Woods Hole Oceanographic Institute was founded in 1930. As inhabitants of the largest environment on Earth, microbial marine systems drive changes in every global system, microbes are responsible for virtually all the photosynthesis that occurs in the ocean, as well as the cycling of carbon, nitrogen, phosphorus and other nutrients and trace elements. Microscopic life undersea is incredibly diverse and still poorly understood, for example, the role of viruses in marine ecosystems is barely being explored even in the beginning of the 21st century
Marine biology
–
Only 29 percent of the Earth's surface is land. The rest is ocean, home to marine life. The oceans average nearly four kilometres in depth and are fringed with coastlines that run for 360,000 kilometres.
Marine biology
–
HMS Challenger during its
pioneer expedition of 1872–76
Marine biology
–
Coral reefs form complex marine ecosystems with tremendous
biodiversity.
Marine biology
–
A
crown-of-thorns starfish.
28.
Biomass (ecology)
–
Biomass, is the mass of living biological organisms in a given area or ecosystem at a given time. Biomass can refer to species biomass, which is the mass of one or more species, or to community biomass and it can include microorganisms, plants or animals. The mass can be expressed as the mass per unit area. How biomass is measured depends on why it is being measured, sometimes, the biomass is regarded as the natural mass of organisms in situ, just as they are. For example, in a fishery, the salmon biomass might be regarded as the total wet weight the salmon would have if they were taken out of the water. In other contexts, biomass can be measured in terms of the organic mass, so perhaps only 30% of the actual weight might count. For other purposes, only biological tissues count, and teeth, bones, in some applications, biomass is measured as the mass of organically bound carbon that is present. Apart from bacteria, the total biomass on Earth is about 560 billion tonnes C. The total live biomass of bacteria may be as much as that of plants, the total amount of DNA base pairs on Earth, as a possible approximation of global biodiversity, is estimated at 5.0 x 1037, and weighs 50 billion tonnes. In comparison, the mass of the biosphere has been estimated to be as much as 4 TtC. An ecological pyramid is a representation that shows, for a given ecosystem. A biomass pyramid shows the amount of biomass at each trophic level, a productivity pyramid shows the production or turn-over in biomass at each trophic level. An ecological pyramid provides a snapshot in time of an ecological community, the bottom of the pyramid represents the primary producers. The primary producers take energy from the environment in the form of sunlight or inorganic chemicals and this mechanism is called primary production. The pyramid then proceeds through the trophic levels to the apex predators at the top. When energy is transferred from one level to the next. The remaining ninety percent goes to metabolic processes or is dissipated as heat and this energy loss means that productivity pyramids are never inverted, and generally limits food chains to about six levels. However, in oceans, biomass pyramids can be wholly or partially inverted, terrestrial biomass generally decreases markedly at each higher trophic level
Biomass (ecology)
–
Apart from bacteria, the total global live biomass has been estimated as 560 billion tonnes C, most of which is found in forests.
Biomass (ecology)
–
Shallow aquatic environments, such as
wetlands,
estuaries and
coral reefs, can be as productive as forests, generating similar amounts of new biomass each year on a given area.
Biomass (ecology)
–
Grasses, trees and shrubs have a much higher biomass than the animals that
consume them
Biomass (ecology)
–
The total biomass of bacteria may equal that of plants.
29.
Radula
–
The radula is an anatomical structure that is used by molluscs for feeding, sometimes compared to a tongue. It is a toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus. The radula is unique to the molluscs, and is found in class of mollusc except the bivalves. Within the gastropods, the radula is used in feeding by both herbivorous and carnivorous snails and slugs, the arrangement of teeth on the radula ribbon varies considerably from one group to another. In most of the ancient lineages of gastropods, the radula is used to graze, by scraping diatoms and other microscopic algae off rock surfaces. Predatory marine snails such as the Naticidae use the radula plus an acidic secretion to bore through the shell of other molluscs, other predatory marine snails, such as the Conidae, use a specialized radula tooth as a poisoned harpoon. Predatory pulmonate land slugs, such as the ghost slug, use elongated razor-sharp teeth on the radula to seize, predatory cephalopods, such as squid, use the radula for cutting prey. The introduction of the radula is usually attributed to Alexander von Middendorff in 1847. A typical radula comprises a number of bilaterally-symmetrical self-similar rows of teeth rooted in a radular membrane, the elastic, delicate radular membrane may be a single tongue, or may split into two. See Hyaline shield for more details, the odontophore is the tongue of flesh underlying the radular membrane, and controls the organs protrusion and return. It can be likened to a pulley wheel over which the string is pulled. The radular teeth can generally bend in a sideways direction, in the patellogastropods, though, the teeth lost this ability and became fixed. The radula comprises multiple, identical rows of teeth, often, each tooth can be divided into three sections, a base, a shaft, and a cusp. In radulae that just sweep, rather than rasp, the underlying substrate, the teeth often tesselate with their neighbours, and this interlocking serves to make it more difficult to remove them from the radular ribbon. Each row of radular teeth consists of One central or median tooth On each side, one or more lateral teeth And then beyond that, the morphology of the radula is related to diet. However, it is not fixed per species, some molluscs can adapt the form of their radular teeth according to food sources are abundant. Pointed teeth are best suited to grazing on algal tissue, whereas blunt teeth are preferable if feeding habits entail scraping epiphytes from surfaces. The radula is used in two ways, either as a rake, generally to comb up microscopic, filamentous algae from a surface, or as a rasp
Radula
–
Tracks made by terrestrial gastropods with their radulas, scraping green algae from a surface inside a greenhouse
Radula
–
A chart of the arrangement of the teeth in five basic varieties of
gastropod radula. Red =central tooth (rachis), Green =lateral teeth, Light green =marginal teeth.
Radula
–
Radula and individual tooth of the predatory
ghost slug,
Selenochlamys ysbryda
Radula
–
Microscopic detail of a docoglossan radula showing the denticles or teeth
30.
Herbivore
–
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthparts adapted to rasping or grinding, horses and other herbivores have wide flat teeth that are adapted to grinding grass, tree bark, and other tough plant material. A large percentage of herbivores have mutualistic gut flora that help them digest plant matter and this gut flora is made up of cellulose-digesting protozoans or bacteria living in the herbivores intestines. Herbivore is the form of a modern Latin coinage, herbivora. Richard Owen employed the term in an 1854 work on fossil teeth. Herbivora is derived from the Latin herba meaning a small plant or herb, Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms feed on autotrophs in general are known as primary consumers. Herbivory usually refers to eating plants, fungi, bacteria and protists that feed on living plants are usually termed plant pathogens. Flowering plants that obtain nutrition from other living plants are usually termed parasitic plants, there is however no single exclusive and definitive ecological classification of consumption patterns, each textbook has its own variations on the theme. Insects fed on the spores of early Devonian plants, and the Rhynie chert also provides evidence that organisms fed on plants using a pierce, during the next 75 million years, plants evolved a range of more complex organs, such as roots and seeds. There is no evidence of any organism being fed upon until the middle-late Mississippian,330.9 million years ago, further than their arthropod status, the identity of these early herbivores is uncertain. Hole feeding and skeletonisation are recorded in the early Permian, with surface fluid feeding evolving by the end of that period, Herbivory among four-limbed terrestrial vertebrates, the tetrapods developed in the Late Carboniferous. Early tetrapods were large amphibious piscivores, while amphibians continued to feed on fish and insects, some reptiles began exploring two new food types, tetrapods and plants. The entire dinosaur order ornithischia was composed with herbivores dinosaurs, carnivory was a natural transition from insectivory for medium and large tetrapods, requiring minimal adaptation. In contrast, a set of adaptations was necessary for feeding on highly fibrous plant materials. Arthropods evolved herbivory in four phases, changing their approach to it in response to changing plant communities, tetrapod herbivores made their first appearance in the fossil record of their jaws near the Permio-Carboniferous boundary, approximately 300 million years ago. The earliest evidence of their herbivory has been attributed to dental occlusion, the evolution of dental occlusion led to a drastic increase in plant food processing and provides evidence about feeding strategies based on tooth wear patterns. Examination of phylogenetic frameworks of tooth and jaw morphologes has revealed that dental occlusion developed independently in several lineages tetrapod herbivores and this suggests that evolution and spread occurred simultaneously within various lineages
Herbivore
–
A
deer and two fawns feeding on foliage
Herbivore
–
A
caterpillar feeding on a leaf
Herbivore
–
A
fossil Viburnum lesquereuxii leaf with evidence of insect herbivory; Dakota Sandstone (
Cretaceous) of Ellsworth County, Kansas. Scale bar is 10 mm.
Herbivore
–
Leaf miners feed on leaf tissue between the epidermal layers, leaving visible trails
31.
Omnivore
–
Omnivore /ˈɒmnivɔər/ is a consumption classification for animals that have the capability to obtain chemical energy and nutrients from materials originating from plant and animal origin. Often, omnivores also have the ability to incorporate food sources such as algae, fungi, omnivores come from diverse backgrounds that often independently evolved sophisticated consumption capabilities. For instance, dogs evolved from primarily carnivorous organisms while pigs evolved from primarily herbivorous organisms, what this means is that physical characteristics are often not reliable indicators of whether an animal has the ability to obtain energy and nutrients from both plant and animal matter. The variety of different animals that are classified as omnivores can be placed into categories depending on their feeding behaviors. Frugivores include maned wolves and orangutans, insectivores include swallows and pink fairy armadillos, granivores include large ground finches, all of these animals are omnivores, yet still fall into special niches in terms of feeding behaviors and preferred foods. Being omnivores gives these animals more food security in times or makes possible living in less consistent environments. The word omnivore derives from the Latin omnis, and vora, from vorare, having been coined by the French, traditionally the definition for omnivory was entirely behavioral by means of simply including both animal and vegetable tissue in the diet. This has subsequently conditioned two context specific definitions, behavioral, This definition is used to specify if a species or individual is actively consuming both plant and animal materials. Physiological, This definition is used in academia to specify species that have the capability to obtain energy. Though Carnivora is a taxon for species classification, no equivalent exists for omnivores. The Carnivora order does not include all species, and not all species within the Carnivora taxon are carnivorous. It is common to find physiological carnivores consuming materials from plants or physiological herbivores consuming material from animals, e. g. felines eating grass, from a behavioral aspect, this would make them omnivores, but from the physiological standpoint, this may be due to zoopharmacognosy. Physiologically, animals must be able to both energy and nutrients from plant and animal materials to be considered omnivorous. For instance, it is documented that animals such as giraffes, camels. Felines, which are regarded as obligate carnivores, occasionally eat grass to regurgitate indigestibles, aid with hemoglobin production. Occasionally, it is found that animals historically classified as carnivorous may deliberately eat plant material, for example, in 2013 it was considered that American alligators may be physiologically omnivorous once investigations had been conducted on why they occasionally eat fruits. It was suggested that alligators probably ate fruits both accidentally but also deliberately, life-history omnivores is a specialized classification given to organisms that change their eating habits during their life cycle. Some species, such as grazing waterfowl like geese, are known to eat animal tissue at one stage of their lives
Omnivore
–
Most bear species are omnivores
Omnivore
–
General
Omnivore
–
Population ecology
Omnivore
–
Carnivores
32.
Predation
–
In an ecosystem, predation is a biological interaction where a predator feeds on its prey. Predators may or may not kill their prey prior to feeding on it, but the act of predation often results in the death of the prey, thus predation is often, though not always, carnivory. Other categories of consumption are herbivory, fungivory, and detritivory, all of these are consumer-resource systems. It can often be difficult to separate various types of feeding behaviors. For example, some parasites prey on their host and then lay their eggs on it, for their offspring to feed on it while it continues to live, the key characteristic of predation is the predators direct impact on the prey population. Selective pressures imposed on one another leads to an evolutionary arms race between prey and predator, resulting in various antipredator adaptations. Ways of classifying predation include grouping by trophic level or diet, by specialization, Predators can be classified by their interactions with their prey. Two factors are considered here, how close the predator and prey are, and whether the prey is killed by the predator. A true predator is one that kills and eats another living thing, Predators may hunt actively for prey in pursuit predation, or sit and wait for prey to approach within striking distance, as in ambush predators. Some predation entails venom that subdues a prey before the predator ingests it, as in the box jellyfish, or disables it, in some cases, the venom contributes to the digestion of the prey, as in rattlesnakes and some spiders. In contrast, baleen whales eat millions of microscopic plankton at once, seed and egg predation are true predation, as seeds and eggs are potential organisms. Predators need not eat prey entirely, for example, some predators cannot digest bones, some may eat only part of an organism, but still consistently cause its death. Grazing organisms do not often kill their prey, while some herbivores like zooplankton live on unicellular phytoplankton and therefore, by the individualized nature of the organism, kill their prey, many others only eat a small part of the plant. Grazing livestock may pull some grass out at the roots, but most is simply grazed upon, kelp is frequently grazed in subtidal kelp forests, but regrows at the base of the blade continuously to cope with browsing pressure. Animals may also be grazed upon, female mosquitos land on hosts briefly to gain sufficient proteins for the development of their offspring, starfish may be grazed on, being capable of regenerating lost arms. Parasites can at times be difficult to distinguish from grazers and their feeding behavior is similar in many ways, however they are noted for their close association with their host species. This close living arrangement may be described by the symbiosis, living together. Parasitic organisms range from the mistletoe, a parasitic plant
Predation
–
A
South China tiger (Panthera tigris amoyensis) as the predator feeding on the
blesbuck as the prey
Predation
–
Indian python swallowing a small
chital deer at
Mudumalai National Park
Predation
–
Meat ants feeding on a
cicada; some species can
prey on individuals of far greater size, particularly when working cooperatively.
Predation
–
Leopard (Panthera pardus pardus) killing a young
bushbuck (Tragelaphus sylvaticus) in
Kruger National Park.
33.
Carnivore
–
Animals that depend solely on animal flesh for their nutrient requirements are called obligate carnivores while those that also consume non-animal food are called facultative carnivores. A carnivore that sits at the top of the chain is termed an apex predator. Plants that capture and digest insects are called carnivorous plants, similarly, fungi that capture microscopic animals are often called carnivorous fungi. The word carnivore sometimes refers to the mammalian order Carnivora, while many Carnivora meet the definition of being meat eaters, not all do, and even fewer are true obligate carnivores. In addition, there are plenty of species that are not members of Carnivora. Outside the animal kingdom, there are several genera containing carnivorous plants, the former are predominantly insectivores, while the latter prey mostly on microscopic invertebrates, such as nematodes, amoebae and springtails. Carnivores are sometimes characterized by the type of prey that they consume, for example, animals that eat insects and similar invertebrates primarily or exclusively are called insectivores, while those that eat fish primarily or exclusively are called piscivores. The first tetrapods, or land-dwelling vertebrates, were piscivorous amphibians known as labyrinthodonts and they gave rise to insectivorous vertebrates and, later, to predators of other tetrapods. Carnivores may alternatively be classified according to the percentage of meat in their diet, obligate carnivores or true carnivores depend on the nutrients found only in animal flesh for their survival. For instance, felids including the cat are obligate carnivores requiring a diet of primarily animal flesh. Characteristics commonly associated with carnivores include organs for capturing and disarticulating prey, in truth, these assumptions may be misleading, as some carnivores do not hunt and are scavengers. Thus they do not have the associated with hunting carnivores. Carnivores have comparatively short digestive systems, as they are not required to break down tough cellulose found in plants, many animals that hunt other animals have evolved eyes that face forward, thus making depth perception possible. This is almost universal among mammalian predators, other predators, like crocodiles, as well as most reptiles and amphibians, have sideways facing eyes and hunt by ambush rather than pursuit. The first vertebrate carnivores were fish, and then amphibians that moved on to land, early tetrapods were large amphibious piscivores. Some scientists assert that Dimetrodon was the first terrestrial vertebrate to develop the curved, serrated teeth that enable a predator to eat prey much larger than itself. While amphibians continued to feed on fish and later insects, reptiles began exploring two new types, tetrapods, and later, plants. Carnivory was a transition from insectivory for medium and large tetrapods
Carnivore
–
Lions are obligate carnivores. A major component of their diet is the flesh of large
mammals, like this
African buffalo.
Carnivore
–
The
Venus flytrap, a well known
carnivorous plant
Carnivore
–
This
Bengal tiger 's sharp
teeth and strong jaws are the classical physical traits expected from carnivorous mammalian
predators
Carnivore
–
Carnivores
34.
Achatina
–
Achatina is a genus of medium-sized to very large, air-breathing, tropical land snails, terrestrial pulmonate gastropod mollusks in the family Achatinidae. There are some 200 species of Achatinidae in Sub-Saharan Africa, some species are kept as terrarium animals due to their size and colourful shells. Snails in this genus have medium to large shells which are ovate in shape, species within the genus Achatina include, Achatina achatina Linnaeus,1758 or giant African snail, Agate Snail or Ghana Tiger Snail, from Western Africa grows to be the largest land snail on Earth. Achatina albopicta E. A. Smith,1878 - along the coast of Kenya, Achatina allisa Reeve,1849 Achatina balteata Reeve,1849 - Cameroon to Central Angola. Achatina craveni E. A. Smith,1881 - Congo, Achatina passargei von Martens - Botswana Achatina purpurea Achatina reticulata Pfeiffer,1845 - Zanzibar. Achatina schweinfurthi von Martens,1873 - East Africa, Achatina schinziana Bousson - Botswana Achatina semisculpta Pfeiffer,1845 - East Africa Achatina smithii Achatina stuhlmanni von Martens,1892 - Uganda. Achatina variegata Roissy Achatina vignoniana Morelet,1874 Achatina weynsi Dautzenberg,1891 - Congo Achatina zanzibarica Bourguignat - Tanzania, Achatina zebra Bruguiere,1792 - South Africa. Incertae sedis, Achatina vassei Germain,1918 - The internal anatomy of this species is not known, species brought into synonymuy Achatina gundlachi L. Pfeiffer,1850, synonym of Geostilbia gundlachi Achatinidae Land snails Land snails in captivity
Achatina
–
Achatina
Achatina
35.
Syrinx aruanus
–
Syrinx aruanus, common name the Australian trumpet or false trumpet, is a species of extremely large sea snail measuring up to 91 cm long and weighing up to 18 kg. It is a gastropod mollusk in the family Turbinellidae, and is the only species in the genus Syrinx. This is the largest extant snail species in the world, in 1681, Filippo Bonanni depicted this species in one of the first books ever published that was solely about seashells. The book was entitled, Ricreatione dell occhio e dela mente nell oservation delle Chiociolle, proposta a curiosi delle opere della natura, the taxonomic affinities of Syrinx aruanus were not properly understood for a long time. Until fairly recently it was placed in the family Melongenidae, a detailed taxonomic overview of this species was provided by Harasewych & Petit. This is the largest Recent shelled gastropod, and the largest shelled gastropod by weight, an extremely large species of fossil gastropod is Campanile giganteum. The overall height of the shell of S. aruanus is up to 91 cm, the weight of the shell is about 1800 g. The shell is usually pale apricot in color, however in life it is covered by brown or grey periostracum. The shell color can fade to a creamy yellow, the whole shell has a spindle-like shape. The spire of the shell is high, the whorls usually have a strong keel which can have nodules on it. The shell has a siphonal canal. There are no folds on the columella, unlike some other genera within the same family, juvenile shells show a long tower-shaped protoconch or embryonic shell of 5 whorls, which is usually lost in the adult. This protoconch is about 2.5 cm long and looks so unlike the adult shell that it was described by George Washington Tryon in 1887 as a different species, the weight of the animal can be up to 18 kg. The radula of this species was described in detail by Wells et al and this species occurs in the northern half of Australia and adjacent areas, including eastern Indonesia and Papua New Guinea. These giant snails live on sandy bottoms in the intertidal zone, where it has not been overfished, this snail is locally common. This carnivorous species is specialized for feeding on worms in the genera Polyodontes, Loimia. It may seem unlikely for such a large gastropod to feed on worms and these worms live in tubes, Syrinx aruanus can reach them with its proboscis, which has a length of up to 250 mm. This species is fished both for its very large shell and for its flesh, which is sometimes used as bait
Syrinx aruanus
–
Syrinx aruanus
Syrinx aruanus
–
Dorsal view of a shell
Syrinx aruanus
–
Drawing of creating a nose-pin from the shell of Syrinx aruanus.
36.
Lymnaea
–
Lymnaea is a genus of small to large-sized air-breathing freshwater snails, aquatic pulmonate gastropod mollusks in the family Lymnaeidae, the pond snails. Some species are used in aquaculture under the name Melantho snails, lymnaea is the type genus of the family Lymnaeidae. How many lymnaeid genera are there
Lymnaea
37.
Gastropods
–
The Gastropoda or gastropods, more commonly known as snails and slugs, are a large taxonomic class within the phylum Mollusca. The class Gastropoda includes snails and slugs of all kinds and all sizes from microscopic to large, there are many thousands of species of sea snails and sea slugs, as well as freshwater snails, freshwater limpets, land snails and land slugs. The class Gastropoda contains a vast total of named species, second only to the insects in overall number, the fossil history of this class goes back to the Late Cambrian. There are 611 families of known, of which 202 are extinct. Gastropoda are a part of the phylum Mollusca, and are the most highly diversified class in the phylum, with 65,000 to 80,000 living snail. The anatomy, behavior, feeding, and reproductive adaptations of gastropods vary significantly from one clade or group to another, therefore, it is difficult to state many generalities for all gastropods. The class Gastropoda has an extraordinary diversification of habitats and those gastropods without a shell, and those with only a very reduced or internal shell, are usually known as slugs, those with a shell into which they cannot withdraw are termed limpets. In a number of families of species, such as all the various limpets, the shell is coiled only in the larval stage, in the scientific literature, gastropods were described under gasteropodes by Georges Cuvier in 1795. Cuvier chose gastropod by derivation from the Ancient Greek words γαστήρ stomach, the earlier name univalve means one valve or shell, in contrast to bivalve applied to mollusks such as clams and meaning that those animals possess two valves or shells. At all taxonomic levels, gastropods are second only to the insects in terms of their diversity, Gastropods have the greatest numbers of named mollusc species. However, estimates of the number of gastropod species vary widely. The number of species can be ascertained from estimates of the number of described species of Mollusca with accepted names. But an estimate of the number of Mollusca, including undescribed species, is about 240,000 species. The estimate of 85,000 molluscs includes 24,000 described species of terrestrial gastropods, different estimates for aquatic gastropods give about 30,000 species of marine gastropods, and about 5,000 species of freshwater and brackish gastropods. The total number of living species of snails is about 4,000. There are 444 recently extinct species of gastropods,18 species that are now extinct in the wild and 69 possibly extinct species, the number of prehistoric species of gastropods is at least 15,000 species. Some of the familiar and better-known gastropods are terrestrial gastropods and some live in freshwater. Gastropods have a distribution from the near Arctic and Antarctic zones to the tropics
Gastropods
Gastropods
–
The upper pair of
tentacles on the head of Helix pomatia have eye spots, but the main sensory organs of the snail are sensory receptors for
olfaction, situated in the
epithelium of the tentacles.
Gastropods
–
A 9-hour-old
trochophore of
Haliotis asinina sf -
shell field
38.
Vestigiality
–
Assessment of the vestigiality must generally rely on comparison with homologous features in related species. Typical examples of both occur in the loss of flying capability in island-dwelling species. Vestigial features may take various forms, for example they may be patterns of behavior, anatomical structures, vestigiality, biologically speaking, refers to organisms retaining organs, which have seemingly lost the entirety of the original function. The issue is controversial and not without dispute, nonetheless, vestigial organs are common, the simple fact that it is noncoding DNA does not establish that it is functionless. Furthermore, even if an extant DNA sequence is functionless, it not follow that it has descended from an ancestral sequence of functional DNA. Logically such DNA would not be vestigial in the sense of being the vestige of a functional structure, in contrast pseudogenes have lost their protein-coding ability or are otherwise no longer expressed in the cell. Whether they have any extant function or not, they have lost their former function, Vestigial structures are often called vestigial organs, although many of them are not actually organs. Such vestigial structures typically are degenerate, atrophied, or rudimentary and it is important to avoid confusion of the concept of vestigiality with that of exaptation. Both may occur together in the example, depending on the relevant point of view. In exaptation a structure used for one purpose is modified for a new one. Similarly, the ostrich uses its wings in displays and temperature control, Vestigial characters range from detrimental through neutral to favorable in terms of selection. Vestigiality in its various forms presents many examples of evidence for biological evolution, Vestigial structures have been noticed since ancient times, and the reason for their existence was long speculated upon before Darwinian evolution provided a widely accepted explanation. However, only in recent centuries have anatomical vestiges become a subject of serious study, in 1798, Étienne Geoffroy Saint-Hilaire noted on vestigial structures, His colleague, Jean-Baptiste Lamarck, named a number of vestigial structures in his 1809 book Philosophie Zoologique. Charles Darwin was familiar with the concept of vestigial structures, though the term for them did not yet exist. He listed a number of them in The Descent of Man, including the muscles of the ear, wisdom teeth, the appendix, the bone, body hair. N organ may become rudimentary for its purpose, and be used for a distinct object. In 1893, Robert Wiedersheim published The Structure of Man, a book on human anatomy, for the greater part Organs which may be rightly termed Vestigial. Later versions of Wiedersheims list were expanded to as many as 180 human vestigial organs, Vestigial structures are often homologous to structures that are functioning normally in other species
Vestigiality
–
The
blind mole rat (Spalax typhlus) has tiny eyes completely covered by a layer of skin.
Vestigiality
–
In humans the
vermiform appendix is a vestigial structure; it has lost much of its ancestral function.
39.
Morphology (biology)
–
Morphology is a branch of biology dealing with the study of the form and structure of organisms and their specific structural features. This includes aspects of the appearance, i. e. external morphology, as well as the form and structure of the internal parts like bones and organs. This is in contrast to physiology, which deals primarily with function, Morphology is a branch of life science dealing with the study of gross structure of an organism or taxon and its component parts. The word morphology is from the Ancient Greek don, morphé, meaning form, among other important theorists of morphology are Lorenz Oken, Georges Cuvier, Étienne Geoffroy Saint-Hilaire, Richard Owen, Karl Gegenbaur and Ernst Haeckel. In English-speaking countries, the term molecular morphology has been used for time for describing the structure of compound molecules, such as polymers. Comparative Morphology is analysis of the patterns of the locus of structures within the plan of an organism. Functional Morphology is the study of the relationship between the structure and function of morphological features, experimental Morphology is the study of the effects of external factors upon the morphology of organisms under experimental conditions, such as the effect of genetic mutation. Anatomy is a branch of morphology that deals with the structure of organisms, most taxa differ morphologically from other taxa. Typically, closely related taxa differ much less than more distantly related ones, cryptic species are species which look very similar, or perhaps even outwardly identical, but are reproductively isolated. Conversely, sometimes unrelated taxa acquire a similar appearance as a result of convergent evolution or even mimicry, in addition, there can be morphological differences within a species, such as in Apoica flavissima where queens are significantly smaller than workers. A further problem with relying on morphological data is that what may appear, morphologically speaking, the significance of these differences can be examined through the use of allometric engineering in which one or both species are manipulated to phenocopy the other species. Invention and development of microscopy enable the observation of 3-D cell morphology with both spatial and temporal resolution. The dynamic processes of cell morphology which are controlled by a complex system play an important role in varied important biological process, such as immune. Comparative anatomy Insect morphology Morphometrics Neuromorphology Phenetics Phenotype Phenotypic plasticity Plant morphology
Morphology (biology)
–
Morphology of a male
Caprella mutica
40.
Monophyly
–
In common cladistic usage, a monophyletic group is a taxon which forms a clade, meaning that it consists of an ancestral species and all its descendants. The term is synonymous with the uncommon term holophyly, monophyletic groups are typically characterized by shared derived characteristics. Monophyly is contrasted with paraphyly and polyphyly, as shown in the second diagram, a paraphyletic group consists of all of the descendants of a common ancestor minus one or more monophyletic groups. These definitions have taken time to be accepted. When the cladistic school of thought became mainstream in the 1960s, indeed, taxonomists sometimes used terms without defining them, leading to confusion in the early literature, a confusion which persists. On the broadest scale, definitions fall into two groups, willi Hennig defined monophyly as groups based on synapomorphy. Some authors have sought to define monophyly to include paraphyly as any two or more groups sharing a common ancestor, however, this broader definition encompasses both monophyletic and paraphyletic groups as defined above. Therefore, most scientists today restrict the term monophyletic to refer to groups consisting of all the descendants of one common ancestor, however, when considering taxonomic groups such as genera and species, the most appropriate nature of their common ancestor is unclear. Assuming that it would be one individual or mating pair is unrealistic for sexually reproducing species, some argue that using a broader definition, such as a species and all its descendants, does not really work to define a genus. According to D. M. Glossary of scientific naming Clade Paraphyly Polyphyly Crown group Abbey, graphical explanation of basic phylogenetic terms. Carr, Steven M. Concepts of monophyly, polyphyly & paraphyly
Monophyly
–
Cladogram of the
primates, showing a monophyletic group (the simians, in yellow), a
paraphyletic group (the prosimians, in blue, including the red patch), and a
polyphyletic group (the night-active primates, the
lorises and the
tarsiers, in red)
41.
Helix aspersa
–
Cornu aspersum, known by the common name garden snail, is a species of land snail. As such it is a terrestrial gastropod mollusc in the family Helicidae. Of all terrestrial molluscs, this species may well be the most widely known, in English texts it was classified under the name Helix aspersa for over two centuries, but the prevailing classification now places it in the genus Cornu. Cornu aspersum is native to the Mediterranean area and western Europe, the adult bears a hard, thin calcareous shell 25–40 mm in diameter and 25–35 mm high, with four or five whorls. The body is soft and slimy, brownish-grey, and the animal retracts itself entirely into the shell when inactive or threatened, when injured or badly irritated the animal produces a defensive froth of mucus that might repel some enemies or overwhelm aggressive small ants or the like. It has no operculum, during dry or cold weather it seals the aperture of the shell with a membrane of dried mucus. The epiphragm helps the snail retain moisture and protects it from predators such as some ants. The snails quiescent periods during heat and drought are known as aestivation, when overwintering, Cornu aspersum avoids the formation of ice in its tissues by altering the osmotic components of its blood, this permits it to survive temperatures as low as -5 °C. During aestivation, the collar has the ability to change its permeability to water. The snail also has a mechanism that prevents excessive absorption of water during hibernation. These mechanisms allow Cornu aspersum to avoid either fatal desiccation or hydration during months of either kind of quiescence, during times of activity the snails head and foot or belly emerge. The head bears four tentacles, the two are larger and bear eye-like light sensors, and the lower two are tactile and olfactory sense organs. The snail extends the tentacles by internal pressure of body fluids, the mouth is located beneath the tentacles, and contains a chitinous radula with which the snail scrapes and manipulates food particles. Between 1774 and 1988 all authorities accepted the species as Helix aspersa, however, in a number of publications since 1990, it has been placed in one of aperta and on the accepted interpretation of the ICZN Codes Article 1.3.2 on the Cornu problem. For those who regard Cornu as appropriate, the name can be Cornu aspersum if they not to classify it in Helix. The matter still is subject to resolution, like other Pulmonata, Cornu aspersum is a hermaphrodite, producing both male and female gametes. Reproduction is usually sexual, although self-fertilisation sometimes occurs, during a mating session of several hours, two snails exchange sperm. Cornu aspersum is one of the species uses love darts during mating
Helix aspersa
–
Cornu aspersum
Helix aspersa
–
Cornu aspersum in warm regions commonly emerges in moist weather in winter.
Helix aspersa
–
Sinistral form (exceptional) and dextral form (common)
MHNT
42.
Garlic
–
Garlic is a species in the onion genus, Allium. Its close relatives include the onion, shallot, leek, chive, with a history of several thousand years of human consumption and use, garlic is native to the region between the Mediterranean and China, and has long been a common seasoning worldwide. It was known to Ancient Egyptians, and has used both as a food flavoring and as a traditional medicine. Allium sativum is a bulbous plant and it grows up to 1.2 m in height. Its hardiness is USDA Zone 8 and it is pollinated by bees and other insects. Allium sativum grows in the wild in areas where it has become naturalized, the wild garlic, crow garlic, and field garlic of Britain are members of the species Allium ursinum, Allium vineale, and Allium oleraceum, respectively. In North America, Allium vineale and Allium canadense, known as garlic or wild garlic. So-called elephant garlic is actually a wild leek, and not a true garlic, single clove garlic originated in the Yunnan province of China. A. sativum var. ophioscorodon Döll, called Ophioscorodon, or hard-necked garlic, includes porcelain garlics, rocambole garlic and it is sometimes considered to be a separate species, Allium ophioscorodon G. Don. A. sativum var. sativum, or soft-necked garlic, includes artichoke garlic, silverskin garlic, Garlic is easy to grow and can be grown year-round in mild climates. While sexual propagation of garlic is possible, nearly all of the garlic in cultivation is propagated asexually, in colder climates, cloves are planted in the autumn, about six weeks before the soil freezes, and harvested in late spring or early summer. The cloves must be planted deep enough to prevent freeze/thaw, which causes mold or white rot, Garlic plants can be grown closely together, leaving enough space for the bulbs to mature, and are easily grown in containers of sufficient depth. Garlic does well in loose, dry, well-drained soils in sunny locations, when selecting garlic for planting, it is important to pick large bulbs from which to separate cloves. Large cloves, along with proper spacing in the planting bed, Garlic plants prefer to grow in a soil with a high organic material content, but are capable of growing in a wide range of soil conditions and pH levels. There are different varieties or subspecies of garlic, most notably hardneck garlic, the latitude where the garlic is grown affects the choice of type, as garlic can be day-length sensitive. Hardneck garlic is grown in cooler climates and produces relatively large cloves, whereas softneck garlic is generally grown closer to the equator and produces small. Garlic scapes are removed to all the garlics energy into bulb growth. The scapes can be eaten raw or cooked, Garlic plants are usually hardy and not affected by many pests or diseases
Garlic
–
Garlic
Garlic
–
Flower head
Garlic
–
Italian garlic PDO (Aglio Bianco Polesano)
Garlic
–
Bulbils
43.
Artemisia (plant)
–
Artemisia /ˌɑːrtᵻˈmiːziə/ is a large, diverse genus of plants with between 200 and 400 species belonging to the daisy family Asteraceae. Common names for species in the genus include mugwort, wormwood. Artemisia comprises hardy herbaceous plants and shrubs, which are known for the chemical constituents in their essential oils. Artemisia species grow in climates of both hemispheres, usually in dry or semiarid habitats. Notable species include A. vulgaris, A. tridentata, A. annua, A. absinthium, A. dracunculus, the leaves of many species are covered with white hairs. Most species have strong aromas and bitter tastes from terpenoids and sesquiterpene lactones, which discourage herbivory, Artemisia species are used as food plants by the larvae of a number of Lepidoptera species. Occasionally, some of the species are called sages, causing confusion with the Salvia sages in the family Lamiaceae, the name artemisia ultimately derives from the Greek goddess Artemis, the namesake of Greek Queens Artemisia I and II. A more specific reference may be to Artemisia II of Caria, the aromatic leaves of some species are used for flavouring. Most species have a bitter taste. A. dracunculus is widely used as a herb, particularly important in French cuisine. Artemisia absinthium was used to repel fleas and moths, and in brewing, the aperitif vermouth is a wine flavored with aromatic herbs, but originally with wormwood. The highly potent spirits absinthe and Malört also contain wormwood, Artemisia arborescens is a very bitter herb indigenous to the Middle East used in tea, usually with mint. A few species are grown as ornamental plants, the ones used for clipped bordering. All grow best in free-draining sandy soil, unfertilized, and in full sun, Artemisia stelleriana is known as Dusty Miller, but several other species bear that name, including Jacobaea maritima, Silene coronaria, and Centaurea cineraria. Artemisinin and derivatives are a group of compounds with the most rapid action of all current drugs used to treat malaria, treatments containing an artemisinin derivative are now standard treatment worldwide for malaria caused by Plasmodium falciparum. Artemisia cina and other Old World species are the source of the antihelminthic drug, Chinese mugwort, Artemisia argyi, is used in the traditional Chinese medicine. Artemisia has been mentioned and used in culture for centuries. A few examples are, Artemisia herba-alba is thought to be the plant translated as wormwood in English language versions of the Bible, Wormwood is mentioned seven times in the Jewish Bible, always with the implication of bitterness
Artemisia (plant)
–
Artemisia
Artemisia (plant)
–
Artemisia pycnocephala (beach sagewort) flowers
Artemisia (plant)
–
Artemisia abrotanum
Artemisia (plant)
–
Artemisia annua
44.
Copper
–
Copper is a chemical element with symbol Cu and atomic number 29. It is a soft, malleable, and ductile metal with high thermal and electrical conductivity. A freshly exposed surface of copper has a reddish-orange color. Copper is one of the few metals that occur in nature in directly usable metallic form as opposed to needing extraction from an ore and this led to very early human use, from c.8000 BC. Copper used in buildings, usually for roofing, oxidizes to form a green verdigris, Copper is sometimes used in decorative art, both in its elemental metal form and in compounds as pigments. Copper compounds are used as agents, fungicides, and wood preservatives. Copper is essential to all living organisms as a trace dietary mineral because it is a key constituent of the enzyme complex cytochrome c oxidase. In molluscs and crustaceans, copper is a constituent of the blood pigment hemocyanin, replaced by the hemoglobin in fish. In humans, copper is found mainly in the liver, muscle, the adult body contains between 1.4 and 2.1 mg of copper per kilogram of body weight. The filled d-shells in these elements contribute little to interatomic interactions, unlike metals with incomplete d-shells, metallic bonds in copper are lacking a covalent character and are relatively weak. This observation explains the low hardness and high ductility of single crystals of copper, at the macroscopic scale, introduction of extended defects to the crystal lattice, such as grain boundaries, hinders flow of the material under applied stress, thereby increasing its hardness. For this reason, copper is supplied in a fine-grained polycrystalline form. The softness of copper partly explains its high conductivity and high thermal conductivity. The maximum permissible current density of copper in open air is approximately 3. 1×106 A/m2 of cross-sectional area, Copper is one of a few metallic elements with a natural color other than gray or silver. Pure copper is orange-red and acquires a reddish tarnish when exposed to air, as with other metals, if copper is put in contact with another metal, galvanic corrosion will occur. A green layer of verdigris can often be seen on old structures, such as the roofing of many older buildings. Copper tarnishes when exposed to sulfur compounds, with which it reacts to form various copper sulfides. There are 29 isotopes of copper, 63Cu and 65Cu are stable, with 63Cu comprising approximately 69% of naturally occurring copper, both have a spin of 3⁄2
Copper
–
Native copper (~4 cm in size)
Copper
–
A copper disc (99.95% pure) made by
continuous casting;
etched to reveal
crystallites.
Copper
–
Copper just above its melting point keeps its pink luster color when enough light outshines the orange
incandescence color.
Copper
–
Unoxidized copper wire (left) and oxidized copper wire (right).
45.
Decollate snail
–
The decollate snail, scientific name Rumina decollata, is a medium-sized predatory land snail, a species of terrestrial pulmonate gastropod mollusk in the family Subulinidae. It is a European species that has introduced in a number of areas worldwide. This species is native to the Mediterranean excluding south-east Mediterranean and it is introduced in Israel and in Egypt since Roman times. It has been introduced into North America, including Phoenix and Glendale, Arizona and it is found in Great Britain, as a hothouse alien The shell of the decollate snail is long and roughly cone-shaped. Rumina decollata is a predator, and feeds readily upon common garden snails and slugs. The snail eats plant matter as well, but the damage it causes to plants is considered minor when compared with the benefit of its predation on garden snails, unfortunately it will also consume harmless local species of land gastropods, and beneficial annelids. Decollate snails are tolerant of dry and cold conditions, during which they burrow deep into the soil and they are most active during the night and during rainfall. Rumina decollata on the UF / IFAS — Featured Creatures website, a photo of decollates feeding on Helix
Decollate snail
–
Rumina decollata
Decollate snail
–
Front view of decollate snail from
Austin, Texas
46.
Biological pest control
–
Biological control is a method of controlling pests such as insects, mites, weeds and plant diseases using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms and it can be an important component of integrated pest management programs. Natural enemies of pests, also known as biological control agents, include predators, parasitoids, pathogens. Biological control agents of plant diseases are most often referred to as antagonists, Biological control agents of weeds include seed predators, herbivores and plant pathogens. DeBach and K. S. Hagen in 1964, however, the practice has previously been used for centuries. Without such ants, southern citrus fruits will be severely insect-damaged, the ants used are known as huang gan ants. Biological control techniques as we know them today started to emerge in the 1870s, during this decade, in the USA, the Missouri State Entomologist C. V. Riley and the Illinois State Entomologist W. LeBaron began within-state redistribution of parasitoids to control crop pests. The United States Department of Agriculture initiated research in biological control following the establishment of the Division of Entomology in 1881. The first importation of a parasitoid into the United States was this of Cotesia glomerata in 1883–1884, imported from Europe to control the imported cabbage white butterfly, Pieris rapae. In 1888–1889 the vedalia beetle, Rodolia cardinalis, which is a ladybug, was introduced from Australia to California to control the cottony cushion scale, Icerya purchasi. This had become a problem for the newly developed citrus industry in California. This great success led to further introductions of beneficial insects into the USA, as a result, nine parasitoids of gypsy moth, seven of brown-tail moth, and two predators for both moths became established in the USA. Although the gypsy moth was not fully controlled by natural enemies, the frequency, duration, and severity of its outbreaks were reduced. This program also led to the development of concepts, principles. The first reported case of a biological control attempt in Canada involves the hymenopteran parasitoid Trichogramma minutum. Between 1884 and 1908, the first Dominion Entomologist, James Fletcher, continued introductions of other parasitoids, there are three basic biological pest control strategies, importation, augmentation and conservation. Importation or classical biological control involves the introduction of a pests natural enemies to a new locale where they do not occur naturally, early instances were often unofficial and not based on research, and some introduced species became serious pests themselves. To be most effective at controlling a pest, a control agent requires a colonizing ability which allows it to keep pace with the spatial and temporal disruption of the habitat
Biological pest control
–
Syrphus fly larva feeding on
aphids.
Biological pest control
–
Hippodamia convergens, the convergent lady beetle, is commonly sold for biological control of
aphids.
Biological pest control
–
Parasitic wasp
Cotesia congregata on tobacco hornworm
Manduca sexta.
Biological pest control
–
A turnaround flowerpot, filled with straw to attract
Dermaptera -species
47.
Heliciculture
–
Perhaps the best known edible land snail species in the Western world is Helix pomatia. This snail is located throughout much of Europe, Helix aspersa, being next most known, were found originally in the Mediterranean region. Helix aspera are now common in parts of North America, Central America. Roasted snail shells have been found in excavations, an indication that snails have been eaten since prehistoric times. Lumaca romana, was an ancient method of farming or heliciculture in the region about Tarquinia. This snail farming method was described by Fulvius Lippinus and mentioned by Marcus Terentius Varro in De Re rustica III,12, the snails were fattened for human consumption using spelt and aromatic herbs. People usually raised snails in pens near the house, and these pens were called cochlea, the Romans, in particular, are known to have considered escargot as an elite food, as noted in the writings of Pliny. The Romans selected the best snails for breeding, shells of the edible land snail species Otala lactea have been recovered in archaeological excavations of Volubilis in present-day Morocco. Pliny described the garden of Fulvius Hirpinus 2,000 years ago as having separate sections for different species of snails. Hirpinus allegedly fed his snails on meal and wine, wall fish were also often eaten in Britain, but were never as popular as on the continent. There, people often ate snails during Lent, and in a few places, they consumed large quantities of snails at Mardi Gras or Carnival, according to some sources, the French exported brown garden snails to California in the 1850s, raising them as the delicacy escargot. Other sources claim that Italian immigrants were the first to bring the snail to the United States, U. S. imports of snails were worth more than $4.5 million in 1995 and came from 24 countries. This includes preserved or prepared snails and snails that are live, fresh, chilled, major exporters to the U. S. are France, Indonesia, Greece and China. The U. S. exported live, fresh, chilled, or frozen snails worth $55,000 to 13 countries, most were shipped to Japan, the Netherlands, and the United Kingdom. Individual statistics are not available for U. S. exports of prepared or processed snails from the U. S. Department of Commerce. Edible land snails range in size from one millimeter long to the giant African snails. Escargot most commonly refers to either Helix aspersa or to Helix pomatia, Achatina fulica, a giant African snail, is sliced and canned and passed off on some consumers as escargot. Terms such as garden snail or common garden snail are rather meaningless since they refer to so many types of snails
Heliciculture
–
A snail farm near
Eyragues,
Provence,
France
Heliciculture
–
Three different species of snails for sale in a market in
Torino,
Italy
Heliciculture
–
Cepaea nemoralis
Heliciculture
–
Achatina fulica
48.
Escargot
–
The escargot is a cooked land snail. Escargots are usually served as a starter in Portugal, Spain and in France, the word escargot is also sometimes applied to the living snails of those species which are commonly eaten in this way. May 24th has been designated National Escargot Day in the United States, the Online Etymological Dictionary writes, The form of the word in Provençal and French seems to have been influenced by words related to scarab. Not all species of snail are edible, and many are too small to make it worthwhile to prepare. Even among the species, the palatability of the flesh varies from species to species. In France, the species Helix pomatia is most often eaten, the petit-gris Cornu aspersa is also eaten, as is Helix lucorum. Several additional species, such as Elona quimperiana, are popular in Europe, Snail shells have been found in archaeological excavations, indicating snails have been eaten since prehistoric times. A number of sites around the Mediterranean have been excavated yielding physical evidence of culinary use of several species of snails. The Romans in particular are known to have considered escargot an elite food, the edible species Otala lactea has been recovered from the Roman-era city Volubilis in present-day Morocco. More recently, African land snails have been known to be edible, in the late 1980s, escargots represented a $300-million-a-year business in the United States. In French cuisine, the snails are typically purged, killed, removed from their shells, and cooked, additional ingredients may be added, such as garlic, thyme, parsley and pine nuts. Special snail tongs and snail forks are normally provided. In Maltese cuisine, snails of the petit gris variety are simmered in red wine or ale with mint, basil, the snails are cooked, and served in their shells. Like most molluscs, escargots are high in protein and low in fat content, escargots are estimated to contain 15% protein,2. 4% fat and about 80% water. The snails are first prepared by purging them of the undesirable contents of their digestive systems. The process used to accomplish this varies, but generally involves a combination of fasting and purging or simply feeding them on a wholesome replacement, the methods most often used can take several days. Farms producing Helix aspersa for sale exist in Europe and in the United States, in both regions, escargot are considered a delicacy. Farm-raised snails are fed a diet of ground cereals
Escargot
–
Escargots with special tongs and fork
Escargot
–
Cooking escargots
Escargot
–
Escargot cooked with garlic butter and parsley in a shell (with a
€0.02 coin, about 19 mm across, as a scale object)
49.
French cuisine
–
French cuisine consists of the cooking traditions and practices from France. In the 14th century Guillaume Tirel, a chef known as Taillevent, wrote Le Viandier. During that time, French cuisine was influenced by Italian cuisine. Cheese and wine are a part of the cuisine. They play different roles regionally and nationally, with many variations, gastro-tourism and the Guide Michelin helped to acquaint people with the rich bourgeois and peasant cuisine of the French countryside starting in the 20th century. Gascon cuisine has also had influence over the cuisine in the southwest of France. Many dishes that were once regional have proliferated in variations across the country, knowledge of French cooking has contributed significantly to Western cuisines. Its criteria are used widely in Western cookery school boards and culinary education, in November 2010, French gastronomy was added by the UNESCO to its lists of the worlds intangible cultural heritage. In French medieval cuisine, banquets were common among the aristocracy, multiple courses would be prepared, but served in a style called service en confusion, or all at once. Food was generally eaten by hand, meats being sliced off in large pieces held between the thumb and two fingers, the sauces were highly seasoned and thick, and heavily flavored mustards were used. Meals often ended with an issue de table, which changed into the modern dessert. The ingredients of the time varied according to the seasons and the church calendar, and many items were preserved with salt, spices, honey. Late spring, summer, and autumn afforded abundance, while winter meals were more sparse, livestock were slaughtered at the beginning of winter. Beef was often salted, while pork was salted and smoked, bacon and sausages would be smoked in the chimney, while the tongue and hams were brined and dried. Cucumbers were brined as well, while greens would be packed in jars with salt, fruits, nuts and root vegetables would be boiled in honey for preservation. Whale, dolphin and porpoise were considered fish, so during Lent, artificial freshwater ponds held carp, pike, tench, bream, eel, and other fish. Poultry was kept in yards, with pigeon and squab being reserved for the elite. Game was highly prized, but very rare, and included venison, wild boar, hare, rabbit, kitchen gardens provided herbs, including some, such as tansy, rue, pennyroyal, and hyssop, which are rarely used today
French cuisine
–
A
nouvelle cuisine presentation
French cuisine
–
French
haute cuisine presentation
French cuisine
–
French wines are usually made to accompany French cuisine
French cuisine
–
John, Duke of Berry enjoying a grand meal. The Duke is sitting with a
cardinal at the high table, under a luxurious
baldaquin, in front of the fireplace, tended to by several servants, including a
carver. On the table to the left of the Duke is a golden
salt cellar, or nef, in the shape of a ship; illustration from
Très Riches Heures du Duc de Berry, circa 1410.
. PMID 20973994. doi:10.1186/1471-2148-10-323.
