Ophidiiformes is an order of ray-finned fish that includes the cusk-eels, pearlfishes, viviparous brotulas, and others. Members of this order have small heads and long slender bodies. They have either smooth scales or no scales, a long dorsal fin and an anal fin that typically runs into the caudal fin. They mostly come from the tropics and subtropics, and live in both freshwater and marine habitats, including abyssal depths. They have adopted a range of feeding methods and lifestyles, including parasitism. The majority are egg-laying, but some are viviparous.
The cusk-eel family, Ophidiidae, is a group of marine bony fishes in the Ophidiiformes order. The scientific name is from the Greek ophis meaning "snake", and refers to their eel-like appearance. True eels, however, diverged from other ray-finned fish during the Jurassic, while cusk-eels are part of the Percomorpha clade, along with tuna, perch, seahorses, and others.
Saccogaster is a genus of viviparous brotulas. They are found in the western Atlantic and Indo-Pacific.
Bellottia is a genus of viviparous brotulas which is found in the subtropical waters of the North Atlantic, the Mediterranean Sea and the Indo-Pacific.
Bidenichthys is a genus of viviparous brotulas.
Hephthocara is a small genus of Indo-Pacific viviparous brotula.
Eurypleuron is a genus of pearlfishes, with these currently recognized species:
Otophidium is a genus of cusk-eels, part of the subfamily Ophidiinae in the family Ophidiidae. They are found in the western Atlantic and eastern Pacific.
Parophidion is a genus of cusk-eels found in the Atlantic Ocean and the Mediterranean Sea.
The faceless cusk is a genus of cusk-eel found in the Indian and Pacific Oceans at depths from 3,935 to 5,100 m. This species grows to 46.5 cm (18.3 in) in standard length.
The band cusk-eel is a fish species in the family Ophidiidae. Widespread in the Western Atlantic from North Carolina, United States, and northern Gulf of Mexico to southeastern Brazil. Absent from The Bahamas. Marine reef-associated tropical demersal fish, up to 30 cm (12 in) long.
Bidenichthys beeblebroxi is a species of common reef fish of the family Bythitidae, and one of three species in the genus Bidenichthys. The species is found in the coastal waters off North Island and northern South Island, New Zealand. It is a common, uniformly gray-brown fish, ranging from SL 6.5–9.5 centimetres long in one study, found in holes beneath rocks and boulders in kelp forest and other reef habitats from the surface down to depths of 30 metres (98 ft). The species was described by Paulin in 1995.
Bidenichthys capensis, the freetail brotula, is an uncommon South African fish of the family Bythitidae, and one of three species, and the type species, of the genus Bidenichthys. The species is found in intertidal zones and rocky tidepools ranging from East London to the Cape of Good Hope, South Africa. It grows up to 90 mm long TL.
Brotulotaenia brevicauda is a benthopelagic marine fish species in the family Ophidiidae. This totally black fish is usually found in the Atlantic Ocean but it has also been reported in the Indian. B. brevicauda lives in deep water and grows up to 32 cm in length. It is also occasionally known as the Short-tail cusk-eel.
Brosmophycinae is a subfamily of the viviparous brotulas. They are divided from the subfamily Bythitinae by having the dorsal fin, caudal fin and anal fin all separate whereas they are joined in the Bythitinae. It is divided into the tribes Dinematichthyini and Brosmophycini, with the first having hardened genital claspers and the second soft genital claspers. A review in 2016 elevated the Dinematichthyini to the status of a family the Dinematichthyidae.
Brosmophycini is a tribe of viviparous brotula, one of two tribes in the subfamily Brosmophycinae. They are distinguished from the other brosmophycin tribe, the Dinematichthyini, by having a male intromittent organ which has no ossified parts, a scale-covered body and well developed gill rakers.
Bythitinae is a subfamily of viviparous brotulas, one of the two subfamilies in the family Bythitidae. This subfamily is characterised by having the dorsal, caudal and anal fins combined. They are mostly found in temperate to tropical seas, from reefs to the benthopelagic zone, but some species from the North Atlantic Ocean occur in into Arctic waters.
Bythitoidei is a suborder of the order Ophidiiformes, the cusk eels. They are distinguished from the other Ophidiform suborder, the Ophidioidei, by being largely viviparous.
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.
Echiodon neotes is a fish species described by Markle and Olney, 1990. Echiodon neotes is part of the genus Echiodon and the subfamily Carapinae.
