The blue danio or Kerr's danio,Turquoise danio is a tropical fish belonging to the genus Danio in family Cyprinidae. The blue danio is found on Ko Yao Yai in Malaysia, it is a blue-colored, deep-bodied danio with several pinkish/gold lines from tail to gills which may or may not be continuous, over a powder blue side. The blue danio is a peaceful, active schooling fish, so is kept in groups, they still need plenty of space to school. Blue danios are kept in water with a 6.5 – 7.0 pH, a water hardness of 8 – 12 dGH, a temperature range of 73 – 77 °F. Blue danios are egg-scatterers, they will spawn at the first light of day. The eggs will hatch in about 36 hours; the taxonomic name honors A. F. G. Kerr, who collected the first specimen on Ko Yao Yai in 1929. Froese and Daniel Pauly, eds.. Danio kerri in FishBase. April 2004 version. "Turquoise Danio". Drs. Foster & Smith's LiveAquaria.com. Retrieved 15 December 2004. Danio kerri
Actinopterygii, or the ray-finned fishes, constitute a class or subclass of the bony fishes. The ray-finned fishes are so called because their fins are webs of skin supported by bony or horny spines, as opposed to the fleshy, lobed fins that characterize the class Sarcopterygii; these actinopterygian fin rays attach directly to the proximal or basal skeletal elements, the radials, which represent the link or connection between these fins and the internal skeleton. Numerically, actinopterygians are the dominant class of vertebrates, comprising nearly 99% of the over 30,000 species of fish, they are ubiquitous throughout freshwater and marine environments from the deep sea to the highest mountain streams. Extant species can range in size from Paedocypris, at 8 mm, to the massive ocean sunfish, at 2,300 kg, the long-bodied oarfish, at 11 m. Ray-finned fishes occur in many variant forms; the main features of a typical ray-finned fish are shown in the adjacent diagram. In nearly all ray-finned fish, the sexes are separate, in most species the females spawn eggs that are fertilized externally with the male inseminating the eggs after they are laid.
Development proceeds with a free-swimming larval stage. However other patterns of ontogeny exist, with one of the commonest being sequential hermaphroditism. In most cases this involves protogyny, fish starting life as females and converting to males at some stage, triggered by some internal or external factor. Protandry, where a fish converts from male to female, is much less common than protogyny. Most families use external rather than internal fertilization. Of the oviparous teleosts, most do not provide parental care. Viviparity, ovoviviparity, or some form of parental care for eggs, whether by the male, the female, or both parents is seen in a significant fraction of the 422 teleost families. Viviparity is rare and is found in about 6% of teleost species. Male territoriality "preadapts" a species for evolving male parental care. There are a few examples of fish; the mangrove rivulus is an amphibious, simultaneous hermaphrodite, producing both eggs and spawn and having internal fertilisation.
This mode of reproduction may be related to the fish's habit of spending long periods out of water in the mangrove forests it inhabits. Males are produced at temperatures below 19 °C and can fertilise eggs that are spawned by the female; this maintains genetic variability in a species, otherwise inbred. The earliest known fossil actinopterygiian is Andreolepis hedei. Remains have been found in Russia and Estonia. Actinopterygians are divided into the subclasses Neopterygii; the Neopterygii, in turn, are divided into the infraclasses Teleostei. During the Mesozoic and Cenozoic the teleosts in particular diversified and as a result, 96% of all known fish species are teleosts; the cladogram shows the major groups of actinopterygians and their relationship to the terrestrial vertebrates that evolved from a related group of fish. Approximate dates are from al.. 2012. The polypterids are the sister lineage of all other actinopterygians, the Acipenseriformes are the sister lineage of Neopterygii, Holostei are the sister lineage of teleosts.
The Elopomorpha appears to be the most basic teleosts. The listing below follows Phylogenetic Classification of Bony Fishes with notes when this differs from Nelson, ITIS and FishBase and extinct groups from Van der Laan 2016. Order †? Asarotiformes Schaeffer 1968 Order †? Discordichthyiformes Minikh 1998 Order †? Paphosisciformes Grogan & Lund 2015 Order †? Scanilepiformes Selezneya 1985 Order †Cheirolepidiformes Kazantseva-Selezneva 1977 Order †Paramblypteriformes Heyler 1969 Order †Rhadinichthyiformes Order †Palaeonisciformes Hay 1902 Order †Tarrasiiformes sensu Lund & Poplin 2002 Order †Ptycholepiformes Andrews et al. 1967 Order †Redfieldiiformes Berg 1940 Order †Haplolepidiformes Westoll 1944 Order †Aeduelliformes Heyler 1969 Order †Platysomiformes Aldinger 1937 Order †Dorypteriformes Cope 1871 Order †Eurynotiformes Sallan & Coates 2013 Subclass Cladistii Pander 1860 Order †Guildayichthyiformes Lund 2000 Order Polypteriformes Bleeker 1859 Clade Actinopteri Cope 1972 s.s. Order †Elonichthyiformes Kazantseva-Selezneva 1977 Order †Phanerorhynchiformes Order †Saurichthyiformes Berg 1937 Subclass Chondrostei Order †Birgeriiformes Jin 2001 Order †Chondrosteiformes Order Acipenseriformes Berg 1940 Subclass Neopterygii Regan 1923 sensu Xu & Wu 2012 Order †Pholidopleuriformes Berg 1937 Order †Peltopleuriformes Lehman 1966 Order †Perleidiformes Berg 1937 Order †Luganoiiformes Lehman 1958 Order †Pycnodontiformes Berg 1937 Infraclass Holostei Muller 1844 Division Halecomorpha Cope 1872 sensu Grande & Bemis 1998 Order †Parasemionotiformes Lehman 1966 Order †Ionoscopiformes Grande & Bemis 1998 Order Amiiformes Huxley 1861 sensu Grande & Bemis 1998 Division Ginglymodi Cope 1871 Order †Dapediiformes Thies & Waschkewitz 2015 Order †Semionotiformes Arambourg & Bertin 1958 Order Lepisosteiformes Hay 1929 Clade Teleosteomorpha Arratia 2000 sensu Arratia 2013 Order †Prohaleciteiformes Arratia 2017 Division Aspidorhynchei Nelson, Grand & Wilson 2016 Order †Aspidorhynchiformes Bleeker 1859 Order †Pachycormiformes Berg 1937 Infraclass Teleostei Müller 1844 sensu Arratia 2013 Order †?
Araripichthyiformes Order †? Ligulelliiformes Taverne 2011 Order †? Tselfatiiformes Nelson 1994 Order †Pholidophori
Danio is a genus of small freshwater fish in the family Cyprinidae found in South and Southeast Asia kept in aquaria. They are characterised by a pattern of horizontal stripes, rows of spots or vertical bars; some species have two pairs of long barbels. Species of this genus consume various small aquatic insects and worms; the name "danio" comes from the Bangla name dhani, meaning "of the rice field". Danio was described in the early 19th century by Francis Hamilton. Two of the species included by him in the genus, still remain valid -- D. D. rerio. About a century and with many more species described in the meantime, the genus was split. In 1991, the two genera were recombined. Brachydanio is now a junior synonym of Danio. There are 27 recognized species in this genus: Danio absconditus S. O. Kullander & Britz, 2015 Danio aesculapii S. O. Kullander & F. Fang, 2009 Danio albolineatus Danio annulosus S. O. Kullander, Norén & Mollah, 2015 Danio assamila S. O. Kullander, 2015 Danio catenatus S. O. Kullander, 2015 Danio choprae Hora, 1928 Danio concatenatus S. O. Kullander, 2015 Danio dangila Danio erythromicron Danio feegradei Hora, 1937 Danio flagrans S. O. Kullander, 2012 Danio htamanthinus S. O. Kullander & Norén, 2016 Danio jaintianensis Danio kerri H. M. Smith, 1931 Danio kyathit F. Fang, 1998 Danio margaritatus Danio meghalayensis N. Sen & S. C.
Dey, 1985 Danio muongthanhensis Nguyen, 2001 Danio nigrofasciatus Danio quagga S. O. Kullander, T. Y. Liao & F. Fang, 2009 Danio quangbinhensis Nguyen, Le & Nguyen, 1999 Danio rerio Danio roseus F. Fang & Kottelat, 2000 Danio sysphigmatus S. O. Kullander, 2015 Danio tinwini S. O. Kullander & F. Fang, 2009 Danio trangi Ngo, 2003
The danionins are a group of small minnow-type fish belonging to the family Cyprinidae. Members of this group are in the genera Danio and Rasbora, they are native to the fresh waters of South and Southeast Asia, with fewer species in Africa. Many species are available as aquarium fish worldwide. Danio species tend to have horizontal stripes, rows of spots, or vertical bars, have long barbels. Devario species tend to have vertical or horizontal bars, short rudimentary barbels, if barbels are present at all. All danionins are egg scatterers and breed in the rainy season in the wild, they are carnivores living on small crustaceans. The grouping of fish now deemed danionins has been the subject of constant research and speculation throughout the 20th century. Nearly all the fish classed within the genera Danio and Devario were placed in the genus Danio upon discovery. However, in the first part of the 20th century, George S. Myers split them into three genera, Danio and Daniops; the sole species within Myers' Daniops, D. myersi, has long ago been found to be a synonym of Devario laoensis, but his genus Brachydanio lasted for much longer, as it included most of the fish now classed as Danio, whereas Danio included most of the fish now classed as Devario.
However, Danio dangila and Danio feegradei, both of which had most of the characteristics of the Brachydanio were placed within Danios.. In 1941, H. M. Smith attempted to unite all the Brachydanios and Danios species into one genus on the basis of a fish from Thailand, supposed to bridge the gap, he downgraded both Danio and Brachydanio into subgenera and erected a new subgenus of Allodanio with one member, Allodanio ponticulus, but Myers pointed out that A. ponticulus was a member of the genus Barilius. The danionin group was thought to include Parabarilius, Danio and Danionella. In this scheme, danionins were distinguished from other cyprinids by the uniquely shared character of the "danionin notch", a large and peculiarly shaped indentation in the medial margin of the mandibles. However, all of these categories at that time were informal. Microrasbora was not considered to be a part of the danionins, nor closely related to Danionella, a part of the danionins as understood at that time. In the late 1980s and 1990s, doubts grew about the validity of Brachydanio, with species being referred to their original naming of Danio, Fang Fang determined that the genus Danio, recognized up to that point, was paraphyletic.
Fang restricted Danio to the species in the "D. dangila species group", which at the time comprised nine species including D. dangila, D. rerio, D. nigrofasciatus, D. albolineatus. The only Danio species to have been called Danio were D. dangila and D. feegradei. As D. dangila was the first discovered Danio the name Danio had to remain with D. dangila, why the vast majority of species were moved to Devario. The sister group to Devario was deemed to be a clade formed by Inlecypris and Chela, more controversially, Esomus was found to be the sister group of Danio; the relationships of Sundadanio and Microrasbora remained unresolved. The danionin notch was found to not supported to be a danionin synapomorphy. In another paper, Celestichthys margaritatus was described as a new species of the Danioninae, it is most related to Microrasbora erythromicron. The genus is identified as a danionin due specializations of its lower jaw and its numerous anal fin rays. Though it lacks a danionin notch, Celestichthys exhibits the "danionin mandibular knob", a bony process on the side of the mandible behind the danionin notch or where the notch should be.
This knob is better developed in males than females. The fish of Rasborinae invariably have anal fins with three spines and five rays. Celestichthys has 8-10 anal fin rays. Rasborins have the generalized cyprinid principal caudal fin ray count of 10/9, while all Asian cyprinids with fewer than 10/9 principal caudal fin rays are all diminutive species of Danioninae, including Celestichthys, M. erythromicron and Paedocypris. In 2007, an analysis of the phylogenetic relationships of the described genus Paedocypris was published, placing it as the sister taxon to Sundadanio; the clade formed by these two genera was found to be sister to a clade including many danionin genera, as well as some rasborin genera such as Rasbora and Boraras, making the danionin group paraphyletic without these rasborin genera based on these results. This paper considered the danionin genera to be within a larger Rasborinae. In 2007, another study analyzed the relationships of Danio; these authors considered Rasborinae to have priority over Danioninae, suggesting that they have the same meaning.
Danio was found to be the sister group of a clade including Chela, Microrasbora and Inlecypris, rather than in a clade with either Devario or Esomus as in previous studies. This paper supported the close relationship of "Microrasbora" erythromicron to Danio species.
The Cyprinidae are the family of freshwater fishes, collectively called cyprinids, that includes the carps, the true minnows, their relatives. Called the "carp family", or "minnow family", Cyprinidae is the largest and most diverse fish family and the largest vertebrate animal family in general, with about 3,000 species of which only 1,270 remain extant, divided into about 370 genera.. They range from about 12 mm to the 3-meter Catlocarpio siamensis; this family of fish is one of the few. The family belongs to the ostariophysian order Cypriniformes, of whose genera and species the cyprinids make more than two-thirds; the family name is derived from the Ancient Greek kyprînos. Cyprinids are stomachless fish with toothless jaws. So, food can be chewed by the gill rakers of the specialized last gill bow; these pharyngeal teeth allow the fish to make chewing motions against a chewing plate formed by a bony process of the skull. The pharyngeal teeth are used by scientists to identify species. Strong pharyngeal teeth allow fish such as the common carp and ide to eat hard baits such as snails and bivalves.
Hearing is a well-developed sense in the cyprinids since they have the Weberian organ, three specialized vertebral processes that transfer motion of the gas bladder to the inner ear. The vertebral processes of the Weberian organ permit a cyprinid to detect changes in motion of the gas bladder due to atmospheric conditions or depth changes; the cyprinids are considered physostomes because the pneumatic duct is retained in adult stages and the fish are able to gulp air to fill the gas bladder, or they can dispose excess gas to the gut. Cyprinids are native to North America and Eurasia; the largest known cyprinid is the giant barb, which may grow up to 3 m in length and 300 kg in weight. Other large species that can surpass 2 m are the golden mahseer and mangar; the largest North American species is the Colorado pikeminnow, which can reach up to 1.8 m in length. Conversely, many species are smaller than 5 cm; the smallest known fish is Paedocypris progenetica, reaching 10.3 mm at the longest. All fish in this family most do not guard their eggs.
The bitterlings of subfamily Acheilognathinae are notable for depositing their eggs in bivalve molluscs, where the young develop until able to fend for themselves. Most cyprinids feed on invertebrates and vegetation due to the lack of teeth and stomach. Many species, such as the ide and the common rudd, prey on small fish when individuals become large enough. Small species, such as the moderlieschen, are opportunistic predators that will eat larvae of the common frog in artificial circumstances; some cyprinids, such as the grass carp, are specialized herbivores. For this reason, cyprinids are introduced as a management tool to control various factors in the aquatic environment, such as aquatic vegetation and diseases transmitted by snails. Unlike most fish species, cyprinids increase in abundance in eutrophic lakes. Here, they contribute towards positive feedback as they are efficient at eating the zooplankton that would otherwise graze on the algae, reducing its abundance. Cyprinids are important food fish.
In land-locked countries in particular, cyprinids are the major species of fish eaten because they make the largest part of biomass in most water types except for fast-flowing rivers. In Eastern Europe, they are prepared with traditional methods such as drying and salting; the prevalence of inexpensive frozen fish products made this less important now than it was in earlier times. Nonetheless, in certain places, they remain popular for food, as well as recreational fishing, have been deliberately stocked in ponds and lakes for centuries for this reason. Cyprinids are popular for angling for match fishing and fishing for common carp because of its size and strength. Several cyprinids have been introduced to waters outside their natural ranges to provide food, sport, or biological control for some pest species; the common carp and the grass carp are the most important for example in Florida. In some cases, such as the Asian carp in the Mississippi Basin, they have become invasive species that compete with native fishes or disrupt the environment.
Carp in particular can stir up sediment, reducing the clarity of the water and making it difficult for plants to grow. Numerous cyprinids have become important in the aquarium and fishpond hobbies, most famously the goldfish, bred in China from the Prussian carp. First imported into Europe around 1728, it was much fancied by Chinese nobility as early as 1150 AD and after it arrived there in 1502 in Japan. In the latter country, from the 18th century onwards, the common carp was bred into the ornamental variety known as koi – or more nishikigoi, as koi means "common carp" in Japanese. Other popular aquarium cyprinids include danionins and true barbs. Larger species are bred by the thousands in outdoor ponds in Southeast Asia, trade in these aquarium fishes
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