Animals are multicellular eukaryotic organisms that form the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, grow from a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from 8.5 millionths of a metre to 33.6 metres and have complex interactions with each other and their environments, forming intricate food webs. The category includes humans, but in colloquial use the term animal refers only to non-human animals; the study of non-human animals is known as zoology. Most living animal species are in the Bilateria, a clade whose members have a bilaterally symmetric body plan; the Bilateria include the protostomes—in which many groups of invertebrates are found, such as nematodes and molluscs—and the deuterostomes, containing the echinoderms and chordates.
Life forms interpreted. Many modern animal phyla became established in the fossil record as marine species during the Cambrian explosion which began around 542 million years ago. 6,331 groups of genes common to all living animals have been identified. Aristotle divided animals into those with those without. Carl Linnaeus created the first hierarchical biological classification for animals in 1758 with his Systema Naturae, which Jean-Baptiste Lamarck expanded into 14 phyla by 1809. In 1874, Ernst Haeckel divided the animal kingdom into the multicellular Metazoa and the Protozoa, single-celled organisms no longer considered animals. In modern times, the biological classification of animals relies on advanced techniques, such as molecular phylogenetics, which are effective at demonstrating the evolutionary relationships between animal taxa. Humans make use of many other animal species for food, including meat and eggs. Dogs have been used in hunting, while many aquatic animals are hunted for sport.
Non-human animals have appeared in art from the earliest times and are featured in mythology and religion. The word "animal" comes from the Latin animalis, having soul or living being; the biological definition includes all members of the kingdom Animalia. In colloquial usage, as a consequence of anthropocentrism, the term animal is sometimes used nonscientifically to refer only to non-human animals. Animals have several characteristics. Animals are eukaryotic and multicellular, unlike bacteria, which are prokaryotic, unlike protists, which are eukaryotic but unicellular. Unlike plants and algae, which produce their own nutrients animals are heterotrophic, feeding on organic material and digesting it internally. With few exceptions, animals breathe oxygen and respire aerobically. All animals are motile during at least part of their life cycle, but some animals, such as sponges, corals and barnacles become sessile; the blastula is a stage in embryonic development, unique to most animals, allowing cells to be differentiated into specialised tissues and organs.
All animals are composed of cells, surrounded by a characteristic extracellular matrix composed of collagen and elastic glycoproteins. During development, the animal extracellular matrix forms a flexible framework upon which cells can move about and be reorganised, making the formation of complex structures possible; this may be calcified, forming structures such as shells and spicules. In contrast, the cells of other multicellular organisms are held in place by cell walls, so develop by progressive growth. Animal cells uniquely possess the cell junctions called tight junctions, gap junctions, desmosomes. With few exceptions—in particular, the sponges and placozoans—animal bodies are differentiated into tissues; these include muscles, which enable locomotion, nerve tissues, which transmit signals and coordinate the body. There is an internal digestive chamber with either one opening or two openings. Nearly all animals make use of some form of sexual reproduction, they produce haploid gametes by meiosis.
These fuse to form zygotes, which develop via mitosis into a hollow sphere, called a blastula. In sponges, blastula larvae swim to a new location, attach to the seabed, develop into a new sponge. In most other groups, the blastula undergoes more complicated rearrangement, it first invaginates to form a gastrula with a digestive chamber and two separate germ layers, an external ectoderm and an internal endoderm. In most cases, a third germ layer, the mesoderm develops between them; these germ layers differentiate to form tissues and organs. Repeated instances of mating with a close relative during sexual reproduction leads to inbreeding depression within a population due to the increased prevalence of harmful recessive traits. Animals have evolved numerous mechanisms for avoiding close inbreeding. In some species, such as the splendid fairywren, females benefit by mating with multiple males, thus producing more offspring of higher genetic quality; some animals are capable of asexual reproduction, which results
Frank Mace MacFarland
Frank Mace MacFarland was an American malacologist associated with Stanford University in California. Born in Centralia, MacFarland attended DePauw University, Stanford University and the University of Wurzburg. On August 27, 1902, MacFarland married Olive Knowles Hornbrook. Mrs. MacFarland was a skilled technician and artist whose delicate watercolor paintings illustrated many of his scientific publications. Frank MacFarland was an authority on the life and habits of nudibranchs and he left unfinished a comprehensive monograph on the group, published posthumously in 1966, he played a leading role in organizing the Hopkins Seaside Laboratory in Pacific Grove, California, of which he was in charge from 1910 to 1913 and co-director from 1915 to 1917, in which he maintained an active interest throughout the remainder of his life. MacFarland served as President of the California Academy of Sciences from 1934 to 1946. In 2006, the MacFarland home on the Stanford campus was added to the National Register of Historic Places.
Gastropods named in honor of Frank Mace MacFarland include one genus and four species: Macfarlandaea Ev. Marcus & Gosliner, 1984 accepted as Pleurobranchaea Leue, 1813 Doridopsis macfarlandi Ostergaard, 1955 accepted as Dendrodoris nigra Felimida macfarlandi Platydoris macfarlandi Hanna, 1951 Runcina macfarlandi Gosliner, 1991 MacFarland, F. M. 1897. "Celluläre Studien an Mollusken-eiern. I. Zur Befruchtung des Eies von Pleurophyllidia californica Bergh. II. Die Centrosomen bei der Richtungskörperbildung im Ei von Diaulula sandiegensis Bergh." Zoologische Jahrbücher, Abtheilung für Morphologie 10: 227-264, pls. 18-22. MacFarland, F. M. 1905. "A preliminary account of the Dorididae of Monterey Bay, California." Proceedings of the Biological Society, Washington 18: 35-54. MacFarland, F. M. 1906. "Opisthobranchiate Mollusca from Monterey Bay and vicinity." Bulletin of the Bureau of Fisheries 25: 109-151, pls. 18-31. MacFarland, F. M. 1908. "Northern Opisthobranchiata." The Nautilus 22: 23-24. MacFarland, F. M. 1909.
"The opisthobranchiate Mollusca of the Branner-Agassiz expedition to Brazil." Leland Stanford Junior University Publications, University Series: 1-104, pls. 1-19. MacFarland, F. M. 1912. "The nudibranch family Dironidae." Zoologische Jahrbücher Supplement 15: 515-536, pls. 30-32. MacFarland, F. M. 1918. "The Dolabellinae." Reports on the scientific results of the expedition to the tropical Pacific by the United States Fish commission steamer Albatross, from August, 1899, to June, 1900. XIX. Published by permission of H. M. Smith, U. S. commissioner of fish and fisheries. MacFarland, F. M. 1923. "The morphology of the nudibranch genus Hancockia." Journal of Morphology 38: 65-104, pls. 1-6. MacFarland, F. M. 1925. "The Acanthodorididae of the California coast." The Nautilus 39: 49-65. MacFarland, F. M. 1926. "The Acanthodorididae of the California coast." The Nautilus 39: 94-103, pls. 2-3. MacFarland, F. M. 1929. "Drepania a genus of nudibranchiate mollusks new to California." Proceedings of the California Academy of Sciences 18: 485-496, pl. 35.
MacFarland, F. M. 1931. "Drepanida, new name for Drepania Lafont, preoccupied." The Nautilus 45: 31-32. MacFarland, F. M. 1966. "Studies of opisthobranchiate mollusks of the Pacific coast of North America." Memoirs of the California Academy of Sciences 6: 1-546, pls. 1-72. MacFarland, F. M. & Charles Henry O'Donoghue. 1929. "A new species of Corambe from the Pacific coast of North America." Proceedings of the California Academy of Sciences, series 4, 18: 1-27, pls. 1-3
Slug, or land slug, is a common name for any 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, a reduced shell, or only a small internal shell sea slugs and semislugs. Various taxonomic families of land slugs form part of several quite different evolutionary lineages, which include snails. Thus, the various families of slugs are not related, despite a superficial similarity in the overall body form; the shell-less condition has arisen many times independently during the evolutionary past, thus the category "slug" is a polyphyletic one. Of the six orders of Pulmonata, two – the Onchidiacea and Soleolifera – comprise slugs. A third family, the Sigmurethra, contains various clades of semi-slugs and slugs; 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, which are a terminal branch of the tree.
The family Ellobiidae are polyphyletic. Subinfraorder Orthurethra Superfamily Achatinelloidea Gulick, 1873 Superfamily Cochlicopoidea Pilsbry, 1900 Superfamily Partuloidea Pilsbry, 1900 Superfamily Pupilloidea Turton, 1831 Subinfraorder Sigmurethra Superfamily Acavoidea Pilsbry, 1895 Superfamily Achatinoidea Swainson, 1840 Superfamily Aillyoidea Baker, 1960 Superfamily Arionoidea J. E. Gray in Turnton, 1840 Superfamily Athoracophoroidea Family Athoracophoridae Superfamily Orthalicoidea Subfamily Bulimulinae Superfamily Camaenoidea Pilsbry, 1895 Superfamily Clausilioidea Mörch, 1864 Superfamily Dyakioidea Gude & Woodward, 1921 Superfamily Gastrodontoidea Tryon, 1866 Superfamily Helicoidea Rafinesque, 1815 Superfamily Helixarionoidea Bourguignat, 1877 Superfamily Limacoidea Rafinesque, 1815 Superfamily Oleacinoidea H. & A. Adams, 1855 Superfamily Orthalicoidea Albers-Martens, 1860 Superfamily Plectopylidoidea Moellendorf, 1900 Superfamily Polygyroidea Pilsbry, 1894 Superfamily Punctoidea Morse, 1864 Superfamily Rhytidoidea Pilsbry, 1893 Family Rhytididae Superfamily Sagdidoidera Pilsbry, 1895 Superfamily Staffordioidea Thiele, 1931 Superfamily Streptaxoidea J.
E. Gray, 1806 Superfamily Strophocheiloidea Thiele, 1926 Superfamily Parmacelloidea Superfamily Zonitoidea Mörch, 1864 Superfamily Quijotoidea Jesús Ortea and Juan José Bacallado, 2016 Family Quijotidae The external anatomy of a slug includes the following: Tentacles Like other pulmonate land gastropods, the majority of land slugs have two pairs of'feelers' or tentacles on their head; the upper pair is light sensing and has eyespots at the ends, while the lower pair provides the sense of smell. Both pairs are retractable. Mantle On top of the slug, behind the head, is the saddle-shaped mantle, under this are the genital opening and anus. On one side of the mantle is a respiratory opening, easy to see when open, but difficult to see when closed; 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; this ridge is called a'keel'.
Foot The bottom side of a slug, flat, is called the'foot'. Like all gastropods, a slug moves by rhythmic waves of muscular contraction on the underside of its foot, it secretes a layer of mucus that it travels on, which helps prevent damage to the foot tissues. Around the edge of the foot in some slugs is a structure called the'foot fringe'. Vestigial shell Most slugs retain a remnant of their shell, internalized; this organ serves as storage for calcium salts in conjunction with the digestive glands. An internal shell is present in the Parmacellidae. Adult Philomycidae and Veronicellidae lack shells. Slugs' bodies are made up of water and, without a full-sized shell, their soft tissues are prone to desiccation, 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 and man-made structures, such as planters, to help retain body moisture. Like all other gastropods, they undergo torsion during development.
Internally, slug anatomy shows the effects of this rotation—but externally, the bodies of slugs appear more or less symmetrical, except for the positioning of the pneumostome, on one side of the animal the right-hand side. Slugs produce two types of mucus: one is thin and watery, the other thick and sticky. Both kinds are hygroscopic; the thin mucus spreads from the foot's centre to its edges, whereas the thick mucus spreads from front to back. Slugs produce thick mucus that coats the whole body of the animal; the mucus secreted by the foot contains fibres that help prevent the slug from slipping down vertical surfaces. The "slime trail" a slug leaves behind has some secondary effects: other slugs coming across a slime trail can recognise the slime trail as produced by one of the same species, useful in finding a mate. Following a slime trail is part of the hunting behaviour of some carnivorous slugs. Body mucus provides some protection against predators, as it can make the slug hard to pick up and hold by a bird's beak, for example, the mucus itself can be
The intertidal zone known as the foreshore and seashore and sometimes referred to as the littoral zone, is the area, above water at low tide and underwater at high tide. This area can include many different types of habitats, with many types of animals, such as starfish, sea urchins, numerous species of coral; the well-known area includes steep rocky cliffs, sandy beaches, or wetlands. The area can be a narrow strip, as in Pacific islands that have only a narrow tidal range, or can include many meters of shoreline where shallow beach slopes interact with high tidal excursion. Peritidal zone is similar but a somewhat wider zone, extending from above the highest tide level to below that of the lowest tide level. Organisms in the intertidal zone are adapted to an environment of harsh extremes; the intertidal zone is home to many several species from different taxa including Porifera, Coelenterates, crustaceans, etc. Water is available with the tides but varies from fresh with rain to saline and dry salt with drying between tidal inundations.
Wave splash can dislodge residents from the littoral zone. With the intertidal zone's high exposure to the sun, the temperature range can be anything from hot with full sun to near freezing in colder climates; some microclimates in the littoral zone are ameliorated by local features and larger plants such as mangroves. Adaptation in the littoral zone allows the use of nutrients supplied in high volume on a regular basis from the sea, moved to the zone by tides. Edges of habitats, in this case land and sea, are themselves significant ecologies, the littoral zone is a prime example. A typical rocky shore can be divided into a spray zone or splash zone, above the spring high-tide line and is covered by water only during storms, an intertidal zone, which lies between the high and low tidal extremes. Along most shores, the intertidal zone can be separated into the following subzones: high tide zone, middle tide zone, low tide zone; the intertidal zone is one of a number of marine biomes or habitats, including estuaries, neritic and deep zones.
Marine biologists divide the intertidal region into three zones, based on the overall average exposure of the zone. The low intertidal zone, which borders on the shallow subtidal zone, is only exposed to air at the lowest of low tides and is marine in character; the mid intertidal zone is exposed and submerged by average tides. The high intertidal zone is only covered by the highest of the high tides, spends much of its time as terrestrial habitat; the high intertidal zone borders on the splash zone. On shores exposed to heavy wave action, the intertidal zone will be influenced by waves, as the spray from breaking waves will extend the intertidal zone. Depending on the substratum and topography of the shore, additional features may be noticed. On rocky shores, tide pools form in depressions. Under certain conditions, such as those at Morecambe Bay, quicksand may form; this subregion is submerged - it is only exposed at the point of low tide and for a longer period of time during low tides. This area is teeming with life.
There is a great biodiversity. Organisms in this zone are not well adapted to periods of dryness and temperature extremes; some of the organisms in this area are abalone, sea anemones, brown seaweed, crabs, green algae, isopods, mussels, sculpin, sea cucumber, sea lettuce, sea palms, sea urchins, snails, surf grass, tube worms, whelks. Creatures in this area can grow to larger sizes because there is more available energy in the localized ecosystem. Marine vegetation can grow to much greater sizes than in the other three intertidal subregions due to the better water coverage; the water is shallow enough to allow plenty of light to reach the vegetation to allow substantial photosynthetic activity, the salinity is at normal levels. This area is protected from large predators such as fish because of the wave action and the shallow water; the intertidal region is an important model system for the study of ecology on wave-swept rocky shores. The region contains a high diversity of species, the zonation created by the tides causes species ranges to be compressed into narrow bands.
This makes it simple to study species across their entire cross-shore range, something that can be difficult in, for instance, terrestrial habitats that can stretch thousands of kilometres. Communities on wave-swept shores have high turnover due to disturbance, so it is possible to watch ecological succession over years rather than decades; the burrowing invertebrates that make up large portions of sandy beach ecosystems are known to travel great distances in cross-shore directions as beaches change on the order of days, semilunar cycles, seasons, or years. The distribution of some species has been found to correlate with geomorphic datums such as the high tide strand and the water table outcrop. Since the foreshore is alternately covered by the sea and exposed to the air, organisms living in this environment must have adaptions for both wet and dry conditions. Hazards include being smashed or carried away by rough waves, exposure to dangerously high temperatures, desiccation. Typical inhabit
Hydroids are a life stage for most animals of the class Hydrozoa, small predators related to jellyfish. Some hydroids such as the freshwater Hydra are solitary, with the polyp attached directly to the substrate; when these produce buds, they become grow on as new individuals. The majority of hydroids are colonial; the original polyp is anchored to a solid substrate and forms a bud which remains attached to its parent. This in turn buds and in this way a stem is formed; the arrangement of polyps and the branching of the stem is characteristic of the species. Some species have the polyps budding directly off the stolon; the polyps are connected by epidermis. The epidermis secretes a chitinous skeleton which supports the stem and in some hydroids, the skeleton extends into a cup shape surrounding the polyp. Most of the polyps are gastrozooids or feeding polyps, but some are specialised reproductive structures known as gonozooids. In some species, further specialised zooids are formed
Japan is an island country in East Asia. Located in the Pacific Ocean, it lies off the eastern coast of the Asian continent and stretches from the Sea of Okhotsk in the north to the East China Sea and the Philippine Sea in the south; the kanji that make up Japan's name mean "sun origin", it is called the "Land of the Rising Sun". Japan is a stratovolcanic archipelago consisting of about 6,852 islands; the four largest are Honshu, Hokkaido and Shikoku, which make up about ninety-seven percent of Japan's land area and are referred to as home islands. The country is divided into 47 prefectures in eight regions, with Hokkaido being the northernmost prefecture and Okinawa being the southernmost one; the population of 127 million is the world's tenth largest. 90.7 % of people live in cities. About 13.8 million people live in the capital of Japan. The Greater Tokyo Area is the most populous metropolitan area in the world with over 38 million people. Archaeological research indicates; the first written mention of Japan is in Chinese history texts from the 1st century AD.
Influence from other regions China, followed by periods of isolation from Western Europe, has characterized Japan's history. From the 12th century until 1868, Japan was ruled by successive feudal military shōguns who ruled in the name of the Emperor. Japan entered into a long period of isolation in the early 17th century, ended in 1853 when a United States fleet pressured Japan to open to the West. After nearly two decades of internal conflict and insurrection, the Imperial Court regained its political power in 1868 through the help of several clans from Chōshū and Satsuma – and the Empire of Japan was established. In the late 19th and early 20th centuries, victories in the First Sino-Japanese War, the Russo-Japanese War and World War I allowed Japan to expand its empire during a period of increasing militarism; the Second Sino-Japanese War of 1937 expanded into part of World War II in 1941, which came to an end in 1945 following the Japanese surrender. Since adopting its revised constitution on May 3, 1947, during the occupation led by SCAP, the sovereign state of Japan has maintained a unitary parliamentary constitutional monarchy with an Emperor and an elected legislature called the National Diet.
Japan is a member of the ASEAN Plus mechanism, UN, the OECD, the G7, the G8, the G20, is considered a great power. Its economy is the world's third-largest by nominal GDP and the fourth-largest by purchasing power parity, it is the world's fourth-largest exporter and fourth-largest importer. Japan benefits from a skilled and educated workforce. Although it has renounced its right to declare war, Japan maintains a modern military with the world's eighth-largest military budget, used for self-defense and peacekeeping roles. Japan is a developed country with a high standard of living and Human Development Index, its population enjoys the highest life expectancy and third lowest infant mortality rate in the world, but is experiencing issues due to an aging population and low birthrate. Japan is renowned for its historical and extensive cinema, influential music industry, video gaming, rich cuisine and its major contributions to science and modern technology; the Japanese word for Japan is 日本, pronounced Nihon or Nippon and means "the origin of the sun".
The character nichi means "sun" or "day". The compound therefore means "origin of the sun" and is the source of the popular Western epithet "Land of the Rising Sun"; the earliest record of the name Nihon appears in the Chinese historical records of the Tang dynasty, the Old Book of Tang. At the end of the seventh century, a delegation from Japan requested that Nihon be used as the name of their country; this name may have its origin in a letter sent in 607 and recorded in the official history of the Sui dynasty. Prince Shōtoku, the Regent of Japan, sent a mission to China with a letter in which he called himself "the Emperor of the Land where the Sun rises"; the message said: "Here, I, the emperor of the country where the sun rises, send a letter to the emperor of the country where the sun sets. How are you". Prior to the adoption of Nihon, other terms such as Yamato and Wakoku were used; the term Wa is a homophone of Wo 倭, used by the Chinese as a designation for the Japanese as early as the third century Three Kingdoms period.
Another form of Wa, Wei in Chinese) was used for an early state in Japan called Nakoku during the Han dynasty. However, the Japanese disliked some connotation of Wa 倭, it was therefore replaced with the substitute character Wa, meaning "togetherness, harmony"; the English word Japan derives from the historical Chinese pronunciation of 日本. The Old Mandarin or early Wu Chinese pronunciation of Japan was recorded by Marco Polo as Cipangu. In modern Shanghainese, a Wu dialect, the pronunciation of characters 日本; the old Malay word for Japan, Japun or Japang, was borrowed from a southern coastal Chinese dialect Fukienese or Ningpo – and this Malay word was encountered by Portuguese traders in Southeast Asia in the 16th century. These Early Portuguese traders brought the word
Heterobranchia, the heterobranchs, is a taxonomic clade of snails and slugs, which includes marine and terrestrial gastropod mollusks. Heterobranchia is one of the main clades of gastropods. Heterobranchia comprises three informal groups: the lower heterobranchs, the opisthobranchs and the pulmonates; the three subdivisions of this large clade are quite diverse: The Lower Heterobranchia includes shelled marine and freshwater species. Opisthobranchia are all marine species, some shelled and some not; the internal organs of the opisthobranchs have undergone detorsion. The Pulmonata includes the majority of land snails and slugs, many freshwater snails, a small number of marine species; the mantle cavity of the Pulmonata is modified into an air-breathing organ. They are characterized by detorsion and a symmetrically-arranged nervous system; the pulmonates always lack an operculum and are hermaphroditic. The families included in Heterobranchia have been placed in many different parts of the taxonomic class of gastropods.
Earlier authors considered Heterobranchia to consist of only marine gastropods, conceptualized it as a borderline category, intermediate between the Opisthobranchia & Pulmonata, all the other gastropods. The category Heterostropha within the Heterobranchia, which includes such families as Architectonicidae, the sundial or staircase snails, is characterized by a shell which has a heterostrophic protoconch, in other words the apical whorls are coiled in the opposite plane to the adult whorls; the classification of this group was revised by Ponder & Warén in 1988. According to the older taxonomy of the Gastropoda the Heterobranchia were ranked as a superorder. Heterobranchia is one of the main clades of gastropods. For a detailed taxonomy, see Taxonomy of the Gastropoda #Clade Heterobranchia. Jörger et al. have redefined major groups within the Heterobranchia: they created the new clades Euopisthobranchia and Panpulmonata. A cladogram showing phylogenic relations of Heterobranchia as proposed by Jörger et al.: Dinapoli A..
Phylogeny and Evolution of the Heterobranchia. Thesis, Frankfurt am Main, 176 pp. PDF. Dinapoli A.. "The long way to diversity – Phylogeny and evolution of the Heterobranchia"". Molecular Phylogenetics and Evolution. 55: 60–76. Doi:10.1016/j.ympev.2009.09.019. PMID 19778622