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Ray-finned Fish
Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or horny spines (rays), as opposed to the fleshy, lobed fins that characterize the class Sarcopterygii (lobe-finned fish). 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 (e.g., pelvic and pectoral girdles). By species count, actinopterygians dominate the vertebrates, and they constitute 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 , to the massive ocean sunfish, at , and the long-bodied oarfish, at . The vast majority of Actinoptery ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinocyclocheilus
''Sinocyclocheilus'' is a genus of freshwater fish in the family Cyprinidae endemic to China, where only found in Guangxi, Guizhou and Yunnan.Ma, L.; and Y.-H. Zhao (2012). Cavefish of China. Pp. 107—125 in: White, W.B.; and D.C. Cuvier, editors. Encyclopedia of Caves. Elsevier. Almost all of its species live in or around caves and most of these have adaptions typical of cavefish such as a lack of scales, lack of pigmentation and reduced eyes (some are completely blind). Several species have an unusual hunchbacked appearance and some of the cave-dwellers have a "horn" on the back (above the forehead), the function of which is unclear. In contrast, the ''Sinocyclocheilus'' species that live aboveground, as well as a few found underground, show no clear cavefish adaptions. They are relatively small fish reaching up to in length. The individual species have small ranges and populations, leading to the status of most of the evaluated species as threatened. Many species populations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
