Gadiformes are an order of ray-finned fish, also called the Anacanthini, that includes the cod and its allies. Many major food fish are in this order. They are found in marine waters throughout the world and the vast majority of the species are found in temperate or colder regions. A few species may enter estuaries but only one, the burbot, is a freshwater fish.
Pomacentridae is a family of ray-finned fish, comprising the damselfishes and clownfishes. This family were formerly placed in the order Perciformes but are now regarded as being incertae sedis in the subseries Ovalentaria in the clade Percomorpha. They are primarily marine, while a few species inhabit freshwater and brackish environments. They are noted for their hardy constitutions and territoriality. Many are brightly colored, so they are popular in aquaria.
Fangtooths are beryciform fish of the family Anoplogastridae that live in the deep sea. The name is from Greek anoplo meaning "unarmed" and gaster meaning "stomach". With a circumglobal distribution in tropical and cold-temperate waters, the family contains only two very similar species in one genus, with no known close relatives.
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.
Pleuronectidae, also known as righteye flounders, are a family of flounders. They are called "righteye flounders" because most species lie on the sea bottom on their left sides, with both eyes on their right sides. The Paralichthyidae are the opposite, with their eyes on the left side. A small number of species in Pleuronectidae can also have their eyes on the left side, notably the members of the genus Platichthys.
Holocentridae is a family of ray-finned fish, belonging to the order Beryciformes with the members of the subfamily Holocentrinae typically known as squirrelfish, while the members of Myripristinae typically are known as soldierfish. In Hawaii, they are known by the Japanese name mempachi/menpachi (メンパチ) or the Hawaiian ʻūʻū.
The fish family Psychrotidae contains about 40 recognized species in 9 genera. This family consists of bottom-dwelling marine sculpins shaped like tadpoles, with large heads and bodies that taper back into small, flat tails. The skin is loosely attached and movable, and the layer underneath it is gelatinous. The eyes are placed high on the head, focused forward closer to the tip of the snout. Members of the family generally have small, leaf-like pectoral fins and lack scales, although some species are covered with soft spines. This is important to the species as the depths in which they live are low pressure and they are ambush/opportunistic/foraging predators that do not expend energy unless they are forced to. The blobfish has a long, broad tongue and conical teeth that are largely recurved and are arranged in bands in irregular rows along the premaxillaries; canines are completely absent. Teeth are nonexistent on the palatines and vomer; which make up the hard palate. The blobfish also has a set of specialized pharyngeal teeth that are well developed and paired evenly along the upper and lower portions of the pharyngeal arch. These specialized teeth may aid in the breakdown of food due to the very strategic dependency on whatever food falls from above.
The velvet whalefish is a deep-sea whalefish, the sole known member of its family Barbourisiidae. It is found throughout the tropical and temperate parts of the world's oceans, mainly in the Pacific near Japan and New Zealand, at depths of 300 to 2,000 m. This species seems very closely related to some flabby whalefish and it was initially believed to belong to that family by some. They have been found from 65°N to 40°S in the Atlantic, 50°N to 50°S in the Pacific, and 5–20°S in the Indian Ocean.
The Synodontidae or lizardfishes are benthic (bottom-dwelling) marine and estuarine bony fishes that belong to the aulopiform fish order, a diverse group of marine ray-finned fish consisting of some 15 extant and several prehistoric families. They are found in tropical and subtropical marine waters throughout the world.
Cutthroat eels are a family, Synaphobranchidae, of eels, the only members of the suborder Synaphobranchoidei. They are found worldwide in temperate and tropical seas.
The Ipnopidae are a family of fishes in the order Aulopiformes. They are small, slender fishes, with maximum length ranging from about 10 to 40 cm. They are found in temperate and tropical deep waters of the Atlantic, Indian, and Pacific Oceans.
Nettastomatidae, the duckbill eels or witch eels are a family of eels. The name is from Greek netta meaning "duck" and stoma meaning "mouth".
The Draconettidae, slope dragonets, are a small family of fish in the order Perciformes. They are found in temperate to tropical waters of the Atlantic, Indian and western Pacific Oceans. They are closely related to, and appear similar to, the fish of the Callionymidae. They are small fish, the largest species reaching 12 cm (4.7 in) long. Like the callionymids, they are bottom-dwelling fish, and usually sexually dimorphic.
Aphyonidae is a family of eel-like fishes in the order Ophidiiformes. They are found in tropical and subtropical waters throughout the world. They are deep-sea fishes, living between 2,000 metres (6,600 ft) and 6,000 metres (20,000 ft) depth.
Ogcocephalidae is a family of anglerfish specifically adapted for a benthic lifestyle of crawling about on the seafloor. Ogcocephalid anglerfish are sometimes referred to as batfishes, deep-sea batfishes, handfishes, and seabats. They are found in tropical and subtropical oceans worldwide. They are mostly found at depths between 200 and 3,000 m, but have been recorded as deep as 4,000 m (13,000 ft). A few species live in much shallower coastal waters and, exceptionally, may enter river estuaries.
Berycidae is a small family of deep-sea fishes, related to the squirrelfishes. The family includes the alfonsinos and the nannygais.
The Aulopidae are a small family of aulopiform fish. They are found in most tropical and subtropical oceans, and are commonly known as flagfins.
The Colocongridae, the worm eels or short-tail eels are a family of eels, containing a single genus, Coloconger.
Polymixia is the only extant genus of the order Polymixiiformes and the only genus in Polymixiidae. It contains 10 species, all of which live in deepwater marine environments. They are found in tropical and subtropical waters of the Atlantic, Indian and western Pacific Oceans. They are bottom-dwelling fish, found down to about 800 m (2,600 ft). Most are relatively small fish, although one species is over 40 cm (16 in) in length.
The headlight fish is a species of lanternfish in the family Myctophidae. It is also sometimes referred to as the headlight lanternfish, or even the lanternfish, though it is not the only species to be called this.
