Deep-sea fish are fish that live in the darkness below the sunlit surface waters, that is below the epipelagic or photic zone of the sea. The lanternfish is, by far, the most common deep-sea fish. Other deep-sea fishes include the flashlight fish, cookiecutter shark, bristlemouths, anglerfish, viperfish, and some species of eelpout.
Barracudinas are any member of the marine mesopelagic fish family Paralepididae: 50 or so extant species are found almost worldwide in deep waters. Several genera are known only from fossils dating back to the Ypresian epoch.
Aulopiformes is a diverse order of marine ray-finned fish consisting of some 15 extant and several prehistoric families with about 45 genera and over 230 species. The common names grinners, lizardfishes and allies, or aulopiforms are sometimes used for this group. The scientific name means "Aulopus-shaped", from Aulopus + the standard fish order suffix "-formes". It ultimately derives from Ancient Greek aulós + Latin forma, the former in reference to the elongated shape of many aulopiforms.
Cetomimidae is a family of small, deep-sea cetomimiform fish. They are among the most deep-living fish known, with some species recorded at depths in excess of 3,500 m (11,500 ft). Females are known as flabby whalefishes, Males are known as bignose fishes, while juveniles are known as tapetails and were formerly thought to be in a separate family, dubbed Mirapinnidae. Adults exhibit extreme sexual dimorphism, and the adult males were once thought to be exemplars of still another family, Megalomycteridae.
Grenadiers or rattails are generally large, brown to black gadiform marine fish of the subfamily Macrourinae, the largest subfamily of the family Macrouridae. Found at great depths from the Arctic to Antarctic, members of this subfamily are amongst the most abundant of the deep-sea fish.
Tilefishes are mostly small perciform marine fish comprising the family Malacanthidae. They are usually found in sandy areas, especially near coral reefs.
Fangtooths are beryciform fish of the family Anoplogastridae that live in the deep sea. The name is from the Greek anoplo, meaning "unarmed", and γαστήρ, meaning "stomach". With a worldwide distribution in tropical and cold-temperate waters, the family contains only two very similar species in one genus, with no known close relatives.
Lanternfish are small mesopelagic fish of the large family Myctophidae. One of two families in the order Myctophiformes, the Myctophidae are represented by 246 species in 33 genera, and are found in oceans worldwide. Lanternfishes are aptly named after their conspicuous use of bioluminescence. Their sister family, the Neoscopelidae, are much fewer in number but superficially very similar; at least one neoscopelid shares the common name "lanternfish": the large-scaled lantern fish, Neoscopelus macrolepidotus.
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, the only family of the order Holocentriformes. The members of the subfamily Holocentrinae are 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.
Pelagic fish live in the pelagic zone of ocean or lake waters—being neither close to the bottom nor near the shore—in contrast with demersal fish that live on or near the bottom, and reef fish that are associated with coral reefs.
Demersal fish, also known as groundfish, live and feed on or near the bottom of seas or lakes. They occupy the sea floors and lake beds, which usually consist of mud, sand, gravel or rocks. In coastal waters they are found on or near the continental shelf, and in deep waters they are found on or near the continental slope or along the continental rise. They are not generally found in the deepest waters, such as abyssal depths or on the abyssal plain, but they can be found around seamounts and islands. The word demersal comes from the Latin demergere, which means to sink.
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.
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.
Little velvetfishes or simply velvetfishes are a family, the Aploactinidae, of marine ray-finned fishes classified within the order Scorpaeniformes. They are small fish that have skin with a velvet texture. They live on the sea bottom close to the shore, at depths of up to 100 metres (330 ft). They are found in the Indo-Pacific region.
Waryfishes are deep-sea aulopiform fishes in the small family Notosudidae. They are thought to have a circumglobal distribution in subarctic to subantarctic waters. The family name Notosudidae derives from the Greek noton (back) and Latin sudis.
The Bathysauridae are a small family of deepwater aulopiform fish, related to the telescopefishes. The two species in the family both belong to the genus Bathysaurus. Commonly called deepwater lizardfishes or deepsea lizardfishes, the latter name usually refers to the species B. ferox specifically.
The pearleyes are a family, Scopelarchidae, of aulopiform fishes, distinguished by their unique visual system, with two retinas in each eye.
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 piper gurnard, also known as the piper or the lyre gurnard, is a species of marine, demersal ray-finned fish from the family Triglidae, the gurnards and sea robins. It is found in the eastern Atlantic Ocean and the Mediterranean Sea. It is the only species in the monotypic genus Trigla.
