Information: - The Weberian apparatus is an anatomical structure that connects the swim bladder to the auditory system in fishes belonging to the superorder Ostariophysi. When it is fully developed in adult fish, the elements of the apparatus are sometimes collectively referred to as the Weberian ossicles. The presence of the structure is one of the most important and phylogenetically significant distinguishing characteristics of the Ostariophysi. The structure itself consists of a set of minute bones that originate from the first few vertebrae to develop in an embryonic ostariophysan. These bones grow to physically connect the auditory system, specifically the inner ear, to the swim bladder. The structure acts as an amplifier of sound waves that would otherwise be only slightly perceivable by the inner ear structure alone. - Actinopterygii , or the ray-finned fishes, constitute a class or subclass of the bony fishes. - Fundulidae is the family of topminnows and North American killifishes. The 46 species are native to North America as far south as Yucatan, and to the islands of Bermuda and Cuba, occurring in both freshwater and marine environments. - A fish is any member of a group of organisms that consist of all gill-bearing aquatic craniate animals that lack limbs with digits. They form a sister group to the tunicates, together forming the olfactores. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Tetrapods emerged within lobe-finned fishes, so cladistically they are fish as well. However, traditionally fish are rendered obsolete or paraphyletic by excluding the tetrapods (i.e., the amphibians, reptiles, birds and mammals which all descended from within the same ancestry). Because in this manner the term "fish" is defined negatively as a paraphyletic group, it is not considered a formal taxonomic grouping in systematic biology. The traditional term pisces (also ichthyes) is considered a typological, but not a phylogenetic classification. - Cyprinodontiformes / saprnodntfrmiz / is an order of ray - finned fish , comprising mostly small , freshwater fish . Many popular aquarium fish , such as killifish and live - bearers , are included . They are closely related to the Atheriniformes and are occasionally included with them . A colloquial term for the order as a whole is toothcarps , though they are not actually close relatives of the true carps -- the latter belong to the superorder Ostariophysi , while the toothcarps are Acanthopterygii . The families of Cyprinodontiformes can be divided into three groups : viviparous and ovoviviparous ( all species give live birth ) , and oviparous ( all species egg - laying ) . The live - bearing groups differ in whether the young are carried to term within ( ovoviviparous ) or without ( viviparous ) an enclosing eggshell . Phylogenetically however , one of the two suborders -- the Aplocheiloidei -- contains oviparous species exclusively , as do two of the four superfamilies of the other suborder ( the Cyprinodontoidea and Valencioidea of the Cyprinodontoidei ) . Vivipary and ovovivipary have evolved independently from oviparous ancestors , the latter possibly twice . - Ostariophysi is the second-largest superorder of fish. Members of this superorder are called ostariophysians. This diverse group contains almost 8,000 species, about 28% of known fish species in the world and 68% of freshwater species, and are present on all major continents except Antarctica. They have a number of common characteristics such as an alarm substance and a Weberian apparatus. Members of this group include fish important to people for food, sport, the aquarium industry, and research. - Acanthopterygii (meaning "spiny finned one") is a superorder of bony fishes in the class Actinopterygii. Members of this superorder are sometimes called ray-finned fishes for the characteristic sharp, bony rays in their fins; however this name is often given to the class Actinopterygii as a whole. - A killifish is any of various oviparous (egg-laying) cyprinodontiform fish (including families Aplocheilidae, Cyprinodontidae, Fundulidae, Profundulidae and Valenciidae). Altogether, there are some 1270 different species of killifish, the biggest family being Rivulidae, containing more than 320 species. Because of living in ephemeral waters, the eggs of most killifish can survive periods of partial dehydration. Many of the species rely on such a diapause, since the eggs would not survive more than a few weeks if entirely submerged in water. Like seeds, the eggs can be sent by mail without water. The adults of some species, such as "Kryptolebias marmoratus", can additionally survive out of the water for several weeks. Most killies are small fish, from one to two inches (2.5 to 5cm), with the largest species growing to just under six inches (15cm). - The priapum fishes are a family, Phallostethidae, of atheriniform fish native to freshwater and brackish habitats in southeast Asia. - Cyprinodon is a genus of small pupfishes found in fresh, brackish and salt water. The genus is primarily found in Mexico, the Caribbean Islands and southern United States (Arizona, California, Florida, Nevada, New Mexico, Oklahoma and Texas), but "C. variegatus" occurs as far north as Massachusetts and along the entire Gulf of Mexico coastline, "C. artifrons" occurs in Belize, and "C. dearborni " and "C. variegatus" are found in northern South America. - Diapause, when referencing animal dormancy, is the delay in development in response to regularly and recurring periods of adverse environmental conditions. It is considered to be a physiological state of dormancy with very specific initiating and inhibiting conditions. Diapause is a mechanism used as a means to survive predictable, unfavorable environmental conditions, such as temperature extremes, drought, or reduced food availability. Diapause is most often observed in arthropods, especially insects, and in the embryos of many of the oviparous species of fish in the order Cyprinodontiformes. - The Atheriniformes, also known as the silversides, are an order of ray-finned fishes that includes the Old World silversides and several less-familiar families, including the unusual Phallostethidae. The order includes at least 354 species. They are found worldwide in tropical and temperate marine and freshwater environments. - Aplocheilidae is a family of fish in the order Cyprinodontiformes found in Africa, Asia and South America. This family-group name is well-established, making its use as a single aplocheiloid family more stable along time, besides avoiding the impact of a new name at the family rank for a popular aquarium fish group. Following this proposal, Aplocheilidae includes three subfamilies: Aplocheilinae Bleeker, 1859; Cynolebiinae Hoedeman, 1961 and Nothobranchiinae Garman, 1895. What is the relationship between 'cyprinodontiformes' and 'actinopterygii'?
parent taxon