A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through convergent evolution they have independently evolved external superficial fish-like body plans adapted to their marine environments, including most numerously fish, but also mammals such as cetaceans, and even extinct ancient marine reptiles such as various known species of ichthyosaurs. Most species have only one dorsal fin, but some have two or three.
The tinfoil barb is a tropical Southeast Asian freshwater fish of the family Cyprinidae. This species was originally described as Barbus schwanenfeldii by Pieter Bleeker in 1853, and has also been placed in the genera Barbodes and Puntius. The specific epithet is frequently misspelled schwanefeldii.
The Moronidae is a family of percomorph fishes, commonly called the temperate basses, in the order Moroniformes. These fishes are found in the freshwaters of North America and the coastal waters of the North Atlantic.
The Ariidae or ariid catfish are a family of catfish that mainly live in marine waters with many freshwater and brackish water species. They are found worldwide in tropical to warm temperate zones. The family includes about 143 species.
The nervous shark is a species of requiem shark, and part of the family Carcharhinidae, so named because of its timid behavior in regard to humans. It is common in shallow, coastal waters off northern Australia, Papua New Guinea, and the Solomon Islands. A small brownish or grayish shark typically measuring 1.0–1.3 m (3.3–4.3 ft) long, this species has a short, blunt snout, oval eyes, and a relatively large second dorsal fin. The leading margins of most fins are finely edged with black, and the lower caudal fin lobe is black-tipped.
The Pondicherry shark is an extremely rare species of requiem shark, in the family Carcharhinidae. A small and stocky gray shark, it grows not much longer than 1 m (3.3 ft) and has a fairly long, pointed snout. This species can be identified by the shape of its upper teeth, which are strongly serrated near the base and smooth-edged near the tip, and by its first dorsal fin, which is large with a long free rear tip. Furthermore, this shark has prominent black tips on its pectoral fins, second dorsal fin, and caudal fin lower lobe.
The African brown knifefish, is the only species in the genus Xenomystus of the family Notopteridae. This fish is found in the Chad, Nile, Congo, Ogowe and Niger basins, as well as coastal river basins in Sierra Leone, Liberia, Togo, Benin and Cameroon.
Brachyplatystoma is a genus of catfish from the family Pimelodidae. As the occasionally used common name goliath catfishes indicates, this genus includes some of the largest species of catfish, including the piraíba, B. filamentosum, which reaches up to the region of 3.6 metres (12 ft) in length. Brachyplatystoma are found in the Amazon and Orinoco basins, and other tropical freshwater and brackish habitats in South America. Some species are migratory. These fish are important as food fish and, to some extent, aquarium fish.
Hemibagrus wyckii is a species of catfish of the family Bagridae. It is occasionally called the crystal-eyed catfish or black devil catfish.
The southern redbelly dace, is a North American species of temperate freshwater fish of the family Cyprinidae. The natural geographic range extends from Western New York to Minnesota, and south to Oklahoma, Arkansas, and Alabama. This fish prefers flowing pools of creeks and streams.
Leiarius is a genus of long-whiskered catfishes native to South America. Most of the genus' species are found in the aquarium hobby as ornamental fish.
Pseudolithoxus is a genus of suckermouth armored catfishes with five described species from the basins of the Orinoco, Casiquiare and upper Rio Negro in Venezuela. Additionally, a possibly undescribed species is known from the Trombetas and Nhamundá rivers in Brazil.
Amphilius is a genus of catfishes of the family Amphiliidae.
Epinephelus andersoni, the catface grouper, brown-spotted grouper, catface rockcod or brown spotted rockcod, is a species of marine ray-finned fish, a grouper from the subfamily Epinephelinae which is part of the family Serranidae, which also includes the anthias and sea basses. It is found in the southwestern Indian Ocean where it is associated with reefs.
Paramphilius is a genus of loach catfishes found in Africa.
Malapterurus beninensis is a species of electric catfish native to the African nations of Angola, Benin, Cameroon, the Democratic Republic of the Congo, the Republic of the Congo, Equatorial Guinea, Gabon, Ghana, Nigeria and Togo. This species grows to a length of 22 cm (9 in) SL. Its habitat is lowland marshes, rivers, and lakes.
Diplodus sargus, the white seabream or sargo is a species of marine ray-finned fish belonging to the family Sparidae, which includes the seabreams and porgies. This fish is found in the eastern Atlantic Ocean and in the Mediterranean Sea. It is a target species for commercial fisheries and is grown in aquaculture. D. sargussensu lato was formerly thought to be a widespread species in the eastern Atlantic and western Indian Oceans but the taxa outside of D, sargussensu stricto are now recognised as valid species and are part of the D. sargus species complex.
Schismatogobius insignus is a species of goby endemic to the Philippines. It is a small fish, growing to a maximum length of only 4.4 cm (1.7 in). It is found in coastal marine, brackish, and freshwater habitats.
The West African bichir or retropinnis bichir, is a freshwater fish in the family Polypteridae, is found in the central Congo River basin and Ogooué River in Africa. It is a long, slender fish that grows to a maximum length of about 34 cm (13 in).
