Cypriniformes is an order of ray-finned fish, including the carps, minnows and relatives. This order contains 11-12 families, over 400 genera, more than 4,250 species, with new species being described every few months or so, new genera being recognized frequently, they are most diverse in southeastern Asia, are absent from Australia and South America. Their closest living relatives are the Gymnotiformes and the Siluriformes. Like other orders of the Ostariophysi, fishes of cypriniformes possess a Weberian apparatus, they differ from most of their relatives in having only a dorsal fin on their back. Further differences are the Cypriniformes' unique kinethmoid, a small median bone in the snout, the lack of teeth in the mouth. Instead, they have convergent structures called pharyngeal teeth in the throat. While other groups of fish, such as cichlids possess pharyngeal teeth, the cypriniformes' teeth grind against a chewing pad on the base of the skull, instead of an upper pharyngeal jaw; the most notable family placed here is Cyprinidae.
This is one of the largest families of fish, is distributed across Africa and North America. Most species are freshwater inhabitants, but a considerable number are found in brackish water, such as roach and bream. At least one species is found in the Pacific redfin, Tribolodon brandtii. Brackish water and marine cyprinids are invariably anadromous, swimming upstream into rivers to spawn. Sometimes separated as family Psilorhynchidae, they seem to be specially-adapted fishes of Cyprinidae. Balitoridae and Gyrinocheilidae are families of mountain stream fishes feeding on algae and small invertebrates, they are found only in subtropical Asia. While the former are a speciose group, the latter contain only a handful of species; the suckers are found in temperate North eastern Asia. These large fishes are similar to carps in ecology. Members of Cobitidae common across Eurasia and parts of North Africa. A mid-sized group like the suckers, they are rather similar to catfish in appearance and behaviour, feeding off the substrate and equipped with barbels to help them locate food at night or in murky conditions.
Fishes in the families Cobitidae, Balitoridae and Gyrinocheilidae are called loaches, although it seems that the last do not belong to the lineage of "true" loaches but are related to the suckers. These included all the forms now placed in the superorder Ostariophysi except the catfish, which were placed in the order Siluriformes. By this definition, the Cypriniformes were paraphyletic, so the orders Gonorhynchiformes and Gymnotiformes have been separated out to form their own monophyletic orders; the families of Cypriniformes are traditionally divided into two superfamilies. Superfamily Cyprinioidea contains the carps and minnows and the mountain carps as the family Psilorhynchidae. In 2012 Maurice Kottelat reviewed the superfamily Cobitoidei and under his revision it now consists of the following families: hillstream loaches, Botiidae, true loaches, Gastromyzontidae, sucking loaches, stone loaches, Serpenticobitidae and long-finned loaches. Catostomoidea is treated as a junior synonym of Cobitoidei.
But it seems that it could be split off the Catostomidae and Gyrinocheilidae in a distinct superfamily. While the Cyprinioidea seem more "primitive" than the loach-like forms, they were successful enough never to shift from the original ecological niche of the basal Ostariophysi. Yet, from the ecomorphologically conservative main lineage at least two major radiations branched off; these diversified from the lowlands into torrential river habitats, acquiring similar habitus and adaptations in the process. The mountain carps are apomorphic Cyprinidae close to true carps, or maybe to the danionins. While some details about the phylogenetic structures of this massively diverse family are known – e.g. that Cultrinae and Leuciscinae are rather close relatives and stand apart from Cyprininae – there is no good consensus yet on how the main lineages are interrelated. A systematic list, from the most ancient to the most modern lineages, can thus be given as: Superfamily Cyprinoidei Family Cyprinidae Bonaparte, 1840 and minnows incl.
Psilorhynchidae) Superfamily Cobitoidei Superfamily Catostomoidea Family Catostomidae Agassiz 1850 Superfamily Gyrinocheiloidea Family Gyrinocheilidae Gill 1905 Superfamily Cobitoidea Family Barbuccidae Kottelat 2012 Family Serpenticobitidae Kottelat 2012 Family Botiidae Berg 1940 Family Vaillantellidae Nalbant & Bănărescu 1977 Family Cobitidae Swainson 1838 Family Balitoridae Swainson 1839 Family Gastromyzontidae Fowler 1905 Family Ellopostomatidae Bohlen & Šlechtová 2009 Family Nemacheilidae Regan 1911 Phylogeny based on the work of the following works Cypriniformes include the most primitive of the Ostariophysi in the narrow sense. This is evidenced n
Artemia is a genus of aquatic crustaceans known as brine shrimp. Artemia, the only genus in the family Artemiidae, has changed little externally since the Triassic period; the first historical record of the existence of Artemia dates back to the first half of the 10th century AD from Urmia Lake, with an example called by an Iranian geographer an "aquatic dog", although the first unambiguous record is the report and drawings made by Schlösser in 1757 of animals from Lymington, England. Artemia populations are found worldwide in inland saltwater lakes, but not in oceans. Artemia are able to avoid cohabiting with most types of predators, such as fish, by their ability to live in waters of high salinity; the ability of the Artemia to produce dormant eggs, known as cysts, has led to extensive use of Artemia in aquaculture. The cysts may be stored for long periods and hatched on demand to provide a convenient form of live feed for larval fish and crustaceans. Nauplii of the brine shrimp Artemia constitute the most used food item, over 2000 tonnes of dry Artemia cysts are marketed worldwide annually.
In addition, the resilience of Artemia makes them ideal animals for running biological toxicity assays and it has become a model organism used to test the toxicity of chemicals. Breeds of Artemia are sold as novelty gifts under the marketing name Aqua Dragons; the brine shrimp Artemia comprises a group of seven to nine species likely to have diverged from an ancestral form living in the Mediterranean area about 5.5 million years ago. The Laboratory of Aquaculture & Artemia Reference Center at Ghent University possesses the largest known Artemia cyst collection, a cyst bank containing over 1,700 Artemia population samples collected from different locations around the world. Artemia is a typical primitive arthropod with a segmented body to, attached broad leaf-like appendages; the body consists of 19 segments, the first 11 of which have pairs of appendages, the next two which are fused together carry the reproductive organs, the last segments lead to the tail. The total length is about 8–10 millimetres for the adult male and 10–12 mm for the female, but the width of both sexes, including the legs, is about 4 mm.
The body of Artemia is divided into head and abdomen. The entire body is covered with a thin, flexible exoskeleton of chitin to which muscles are attached internally and shed periodically. In female Artemia a moult precedes every ovulation. For brine shrimp, many functions, including swimming and reproduction are not controlled through the brain. Autotomy, the voluntary shedding or dropping of parts of the body for defence, is controlled locally along the nervous system. Artemia have two types of eyes, they have two separated compound eyes mounted on flexible stalks. These compound eyes are the main optical sense organ in adult brine shrimps; the median eye, or the naupliar eye, is situated anteriorly in the centre of the head and is the only functional optical sense organ in the nauplii, functional until the adult stage. Brine shrimp can tolerate any levels of salinity from 25‰ to 250‰, with an optimal range of 60‰–100‰, occupy the ecological niche that can protect them from predators. Physiologically, optimal levels of salinity are about 30–35‰, but due to predators at these salt levels, brine shrimp occur in natural habitats at salinities of less than 60–80‰.
Locomotion is achieved by the rhythmic beating of the appendages acting in pairs. Respiration occurs on the surface of the legs through fibrous, feather-like plates Males differ from females by having the second antennae markedly enlarged, modified into clasping organs used in mating. Adult female brine shrimp ovulate every 140 hours. In favourable conditions, the female brine shrimp can produce eggs that immediately hatch. While in extreme conditions, such as low oxygen level or salinity above 150‰, female brine shrimp produce eggs with a chorion coating which has a brown colour; these eggs known as cysts, are metabolically inactive and can remain in total stasis for two years while in dry oxygen-free conditions at temperatures below freezing. This characteristic is called cryptobiosis, meaning "hidden life". While in cryptobiosis, brine shrimp eggs can survive temperatures of liquid air and a small percentage can survive above boiling temperature for up to two hours. Once placed in briny water, the eggs hatch within a few hours.
The nauplius larvae are less than 0.4 mm in length. Parthenogenesis is a natural form of reproduction in which growth and development of embryos occur without fertilisation. Thelytoky is a particular form of parthenogenesis in which the development of a female individual occurs from an unfertilised egg. Automixis is a form of thelytoky; the kind of automixis relevant here is one in which two haploid products from the same meiosis combine to form a diploid zygote. Diploid Artemia parthenogenetica reproduce by automictic parthenogenesis with central fusion and low but nonzero recombination. Central fusion of two of the haploid products of meiosis tends to maintain heterozygosity in transmission of the genome from mother to offspring, to minimise inbreeding depression. Low crossover recombination during meiosis restrains the transition from heterozygosity to homozygosity over successive generations. In their first stage of development, Artemia do not feed but consume their own energy reserves stored in
Daphnia, a genus of small planktonic crustaceans, are 0.2–5 millimetres in length. Daphnia are members of the order Cladocera, are one of the several small aquatic crustaceans called water fleas because their saltatory swimming style resembles the movements of fleas. Daphnia live in various aquatic environments ranging from acidic swamps to freshwater lakes and ponds; the two most available species of Daphnia are D. pulex and D. magna. They are associated with a related genus in the order Cladocera: Moina, in the Moinidae family instead of Daphniidae and is much smaller than D. pulex. Daphnia eggs for sale are enclosed in ephippia; the body of Daphnia is 1–5 millimetres long, is divided into segments, although this division is not visible. The head is fused, is bent down towards the body with a visible notch separating the two. In most species, the rest of the body is covered by a carapace, with a ventral gap in which the five or six pairs of legs lie; the most prominent features are the compound eyes, the second antennae, a pair of abdominal setae.
In many species, the carapace is translucent or nearly so and as a result they make excellent subjects for the microscope as one can observe the beating heart. Under low-power microscopy, the feeding mechanism can be observed, with immature young moving in the brood pouch; the heart is at the top of the back, just behind the head, the average heart rate is 180 bpm under normal conditions. Daphnia, like many animals, are prone to alcohol intoxication, make excellent subjects for studying the effects of the depressant on the nervous system due to the translucent exoskeleton and the visibly altered heart rate, they are tolerant of being observed live under a cover slip and appear to suffer no harm when returned to open water. This experiment can be performed using caffeine, nicotine or adrenaline, each producing an increase in the heart rate. Due to its intermediate size, Daphnia utilizes both diffusion and circulatory methods, producing hemoglobin in low-oxygen environments. Daphnia is a large genus – comprising over 200 species – belonging to the cladoceran family Daphniidae.
It is subdivided into several subgenera, but the division has been controversial and is still in development. Each subgenus has been further divided into a number of species complexes; the understanding of species boundaries has been hindered by phenotypic plasticity, intercontinental introductions and poor taxonomic descriptions. Daphnia species are r-selected, meaning that they invest in early reproduction and so have short lifespans. An individual Daphnia life-span depends on factors such as temperature and the abundance of predators, but can be 13–14 months in some cold, oligotrophic fish-free lakes. In typical conditions, the life cycle is much shorter, not exceeding 5–6 months. Daphnia are filter feeders, ingesting unicellular algae and various sorts of organic detritus including protists and bacteria Beating of the legs produces a constant current through the carapace which brings such material into the digestive tract; the trapped food particles are formed into a food bolus which moves down the digestive tract until voided through the anus located on the ventral surface of the terminal appendage.
The second and third pair of legs are used in the organisms' filter feeding, ensuring large unabsorbable particles are kept out, while the other sets of legs create the stream of water rushing into the organism. Swimming is powered by the second set of antennae, which are larger in size than the first set; the action of this second set of antennae is responsible for the jumping motion. Most Daphnia species have a life cycle based on "cyclical parthenogenesis", alternating between parthenogenetic reproduction and sexual reproduction. For most of the growth season, females reproduce asexually, they produce. Under typical conditions, these eggs hatch after a day, remain in the female's brood pouch for around three days, they are released into the water, pass through a further 4–6 instars over 5–10 days before reaching an age where they are able to reproduce. The asexually produced offspring are female. Towards the end of the growing season, the mode of reproduction changes, the females produce tough "resting eggs" or "winter eggs".
When environmental condition deteriorate, some of the asexually produced offspring develop into males. The females start producing haploid sexual eggs. In species without males, resting eggs are produced asexually and are diploid. In either case, the resting eggs are protected by a hardened coat called the ephippium, are cast off at the female's next moult; the ephippia can withstand periods of extreme cold, drought or lack of food availability, hatch – when conditions improve – into females. Several Daphnia species are considered threatened; the following are listed as vulnerable by IUCN: Daphnia nivalis, Daphnia coronata, Daphnia occidentalis, Daphnia jollyi. Some species
A chordate is an animal constituting the phylum Chordata. During some period of their life cycle, chordates possess a notochord, a dorsal nerve cord, pharyngeal slits, an endostyle, a post-anal tail: these five anatomical features define this phylum. Chordates are bilaterally symmetric; the Chordata and Ambulacraria together form the superphylum Deuterostomia. Chordates are divided into three subphyla: Vertebrata. There are extinct taxa such as the Vetulicolia. Hemichordata has been presented as a fourth chordate subphylum, but now is treated as a separate phylum: hemichordates and Echinodermata form the Ambulacraria, the sister phylum of the Chordates. Of the more than 65,000 living species of chordates, about half are bony fish that are members of the superclass Osteichthyes. Chordate fossils have been found from as early as the Cambrian explosion, 541 million years ago. Cladistically, vertebrates - chordates with the notochord replaced by a vertebral column during development - are considered to be a subgroup of the clade Craniata, which consists of chordates with a skull.
The Craniata and Tunicata compose the clade Olfactores. Chordates form a phylum of animals that are defined by having at some stage in their lives all of the following anatomical features: A notochord, a stiff rod of cartilage that extends along the inside of the body. Among the vertebrate sub-group of chordates the notochord develops into the spine, in wholly aquatic species this helps the animal to swim by flexing its tail. A dorsal neural tube. In fish and other vertebrates, this develops into the spinal cord, the main communications trunk of the nervous system. Pharyngeal slits; the pharynx is the part of the throat behind the mouth. In fish, the slits are modified to form gills, but in some other chordates they are part of a filter-feeding system that extracts particles of food from the water in which the animals live. Post-anal tail. A muscular tail that extends backwards behind the anus. An endostyle; this is a groove in the ventral wall of the pharynx. In filter-feeding species it produces mucus to gather food particles, which helps in transporting food to the esophagus.
It stores iodine, may be a precursor of the vertebrate thyroid gland. There are soft constraints that separate chordates from certain other biological lineages, but are not part of the formal definition: All chordates are deuterostomes; this means. All chordates are based on a bilateral body plan. All chordates are coelomates, have a fluid filled body cavity called a coelom with a complete lining called peritoneum derived from mesoderm; the following schema is from the third edition of Vertebrate Palaeontology. The invertebrate chordate classes are from Fishes of the World. While it is structured so as to reflect evolutionary relationships, it retains the traditional ranks used in Linnaean taxonomy. Phylum Chordata †Vetulicolia? Subphylum Cephalochordata – Class Leptocardii Clade Olfactores Subphylum Tunicata – Class Ascidiacea Class Thaliacea Class Appendicularia Class Sorberacea Subphylum Vertebrata Infraphylum incertae sedis Cyclostomata Superclass'Agnatha' paraphyletic Class Myxini Class Petromyzontida or Hyperoartia Class †Conodonta Class †Myllokunmingiida Class †Pteraspidomorphi Class †Thelodonti Class †Anaspida Class †Cephalaspidomorphi Infraphylum Gnathostomata Class †Placodermi Class Chondrichthyes Class †Acanthodii Superclass Osteichthyes Class Actinopterygii Class Sarcopterygii Superclass Tetrapoda Class Amphibia Class Sauropsida Class Synapsida Craniates, one of the three subdivisions of chordates, all have distinct skulls.
They include the hagfish. Michael J. Benton commented that "craniates are characterized by their heads, just as chordates, or all deuterostomes, are by their tails". Most craniates are vertebrates; these consist of a series of bony or cartilaginous cylindrical vertebrae with neural arches that protect the spinal cord, with projections that link the vertebrae. However hagfish have incomplete braincases and no vertebrae, are therefore not regarded as vertebrates, but as members of the craniates, the group from which vertebrates are thought to have evolved; however the cladistic exclusion of hagfish from the vertebrates is controversial, as they ma
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
Binomial nomenclature called binominal nomenclature or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages. Such a name is called a binomen, binominal name or a scientific name; the first part of the name – the generic name – identifies the genus to which the species belongs, while the second part – the specific name or specific epithet – identifies the species within the genus. For example, humans belong within this genus to the species Homo sapiens. Tyrannosaurus rex is the most known binomial; the formal introduction of this system of naming species is credited to Carl Linnaeus beginning with his work Species Plantarum in 1753. But Gaspard Bauhin, in as early as 1623, had introduced in his book Pinax theatri botanici many names of genera that were adopted by Linnaeus; the application of binomial nomenclature is now governed by various internationally agreed codes of rules, of which the two most important are the International Code of Zoological Nomenclature for animals and the International Code of Nomenclature for algae and plants.
Although the general principles underlying binomial nomenclature are common to these two codes, there are some differences, both in the terminology they use and in their precise rules. In modern usage, the first letter of the first part of the name, the genus, is always capitalized in writing, while that of the second part is not when derived from a proper noun such as the name of a person or place. Both parts are italicized when a binomial name occurs in normal text, thus the binomial name of the annual phlox is now written as Phlox drummondii. In scientific works, the authority for a binomial name is given, at least when it is first mentioned, the date of publication may be specified. In zoology "Patella vulgata Linnaeus, 1758"; the name "Linnaeus" tells the reader who it was that first published a description and name for this species of limpet. "Passer domesticus". The original name given by Linnaeus was Fringilla domestica; the ICZN does not require that the name of the person who changed the genus be given, nor the date on which the change was made, although nomenclatorial catalogs include such information.
In botany "Amaranthus retroflexus L." – "L." is the standard abbreviation used in botany for "Linnaeus". "Hyacinthoides italica Rothm. – Linnaeus first named this bluebell species Scilla italica. The name is composed of two word-forming elements: "bi", a Latin prefix for two, "-nomial", relating to a term or terms; the word "binomium" was used in Medieval Latin to mean a two-term expression in mathematics. Prior to the adoption of the modern binomial system of naming species, a scientific name consisted of a generic name combined with a specific name, from one to several words long. Together they formed a system of polynomial nomenclature; these names had two separate functions. First, to designate or label the species, second, to be a diagnosis or description. In a simple genus, containing only two species, it was easy to tell them apart with a one-word genus and a one-word specific name; such "polynomial names" may sometimes look like binomials, but are different. For example, Gerard's herbal describes various kinds of spiderwort: "The first is called Phalangium ramosum, Branched Spiderwort.
The other... is aptly termed Phalangium Ephemerum Virginianum, Soon-Fading Spiderwort of Virginia". The Latin phrases are short descriptions, rather than identifying labels; the Bauhins, in particular Caspar Bauhin, took some important steps towards the binomial system, by pruning the Latin descriptions, in many cases to two words. The adoption by biologists of a system of binomial nomenclature is due to Swedish botanist and physician Carl von Linné, more known by his Latinized name Carl Linnaeus, it was in his 1753 Species Plantarum that he first began using a one-word "trivial name" together with a generic name in a system of binomial nomenclature. This trivial name is what is now known as specific name; the Bauhins' genus names were retained in many of these, but the descriptive part was reduced to a single word. Linnaeus's trivial names introduced an important new idea, namely that the function of a name could be to give a species a unique label; this meant. Thus Gerard's Phalangium ephemerum virginianum became Tradescantia virgi
Trigonostigma is a genus of small cyprinid fish found in Southeast Asia. These social, colorful freshwater fish are kept in aquariums. There are four recognized species in this genus: Trigonostigma espei Trigonostigma hengeli Trigonostigma heteromorpha Trigonostigma somphongsi