The Mastacembelidae are a family of fishes, known as the spiny eels. The Mastacembelids are part of the Order Synbranchiformes, the swamp eels, which are part of the Actinopterygii.
Pearlfish are marine fish in the ray-finned fish family Carapidae. Pearlfishes inhabit the tropical waters of the Atlantic, Indian, and Pacific Oceans at depths to 2,000 m (6,600 ft), along oceanic shelves and slopes. They are slender, elongated fish with no scales, translucent bodies, and dorsal fin rays which are shorter than their anal fin rays. Adults of most species live symbiotically inside various invertebrate hosts, and some live parasitically inside sea cucumbers. The larvae are free living.
Notacanthidae, the deep-sea spiny eels, are a family of fishes found worldwide below 125 m (410 ft), and as deep as 3,500 m (11,500 ft). The earliest known spiny eel is Pronotacanthus sahelalmae, from the Santonian of what is now Lebanon.
Grunters or tigerperches are ray-finned fishes in the family Terapontidae. This family is part of the superfamily Percoidea of the order Perciformes.
The Pacific hagfish is a species of hagfish. It lives in the mesopelagic to abyssal Pacific ocean, near the ocean floor. It is a jawless fish and has a body plan that resembles early paleozoic fish. They are able to excrete prodigious amounts of slime in self-defense.
Macrognathus is a genus of eel-like fish of the family Mastacembelidae of the order Synbranchiformes.
The Carpathian brook lamprey or Danube lamprey is a species of lamprey in the Petromyzontidae family. It is found in Austria, Bosnia and Herzegovina, Bulgaria, Croatia, Czech Republic, Hungary, Moldova, Romania, Serbia, Montenegro, Slovakia, and Ukraine. It is non-parasitic.
The Greek lamprey is a species of jawless fish in the Petromyzontidae family. It is endemic to Greece. Its natural habitats are rivers and freshwater springs. It is threatened by habitat loss. This species may be better included in the genus Caspiomyzon. It is the most endangered species of lamprey. It lives only in the Strymon and Louros river basins.
The Kern brook lamprey is a species of lamprey in the Petromyzontidae family endemic to the United States. It is found on the east side of San Joaquin Valley, in lower Merced, Kaweah, Kings, and San Joaquin rivers in California. It can grow to up to around 14 centimeters, and is characterized by its grayish brown and white coloring, and black spots on its fins.
The Caspian lamprey, Caspiomyzon wagneri, is a species of lamprey native to the Caspian Sea, and a member of the Petromyzontidae family. Eudontomyzon hellenicus and E. graecus also possibly belong in this genus. This species is a non-parasitic lamprey that feeds on animal carcasses.
Notacanthus is a genus of spiny eels in the family Notacanthidae.
The Ohio lamprey is a lamprey found in the Ohio River drainage basin in the United States and is a parasitic species of lampreys. They are considered to be an endangered/rare species in some states, due to siltation, pollution, and construction of dams.
Lipogenys gillii, the blackfin tapirfish, is a species of spiny eel in the family Notacanthidae, the only member of its genus. It is a benthic deep-sea fish occurring along the eastern coast of North America and in the southwestern Pacific near Australia at depths from 400 to 2,000 m.
Brotula is a genus of cusk-eels. It is the only genus is the subfamily Brotulinae.
Brotulotaenia is a genus of cusk-eels. It is the only genus in the subfamily Brotulotaeniinae.
Polypterus palmas, the shortfin or marbled bichir, is a fish in the family Polypteridae found in freshwater environments within a demersal depth range in tropical climates.
Macrognathus aral, the one-stripe spiny eel, is a small fish from Pakistan, India, Bangladesh, Nepal and Myanmar. It usually is found in running and stagnant waters of freshwater and brackish waters. It is 63.5 cm (25.0 in) in length.
Ophidiinae is a subfamily of the cusk eel family Ophidiidae. The species in the subfamily are characterised by having their pelvic fins situated far forward on the body and supported by an forward orientated extension of the pelvic girdle, they lack barbels on the mouth and chin and they are covered in small cycloid scales arranged in horizontal or diagonal rows. Some species have a modified swim bladder and the anterior vertebrae which enables them to generate sounds. and some of these modifications are sexually dimorphic and make the fish capable of generating sound. They have two rays in each ventral fin and the caudal fin has 9 rays. Most species are benthic and occur on the continental shelf.
The longnose tapirfish is a species of deep-sea spiny eel that lives in bathypelagic environments, and is a host of an endoparasite, Brachyenteron rissoanum.
Synbranchinae is a subfamily of swamp eel, consisting of six of the ten genera in the family Synbranchidae. The remaining genus, the monotypic Macrotrema is the only one in the other subfamily Macrotreminae. The subfamily occurs in the Neotropics, Afrotropics and Asia.
