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.
Lancetfishes are large oceanic predatory fishes in the genus Alepisaurus in the monogeneric family Alepisauridae.
The abyssal zone or abyssopelagic zone is a layer of the pelagic zone of the ocean. The word abyss comes from the Greek word ἄβυσσος (ábussos), meaning "bottomless". At depths of 4,000–6,000 m (13,000–20,000 ft), this zone remains in perpetual darkness. It covers 83% of the total area of the ocean and 60% of Earth's surface. The abyssal zone has temperatures around 2–3 °C (36–37 °F) through the large majority of its mass. The water pressure can reach up to 76 MPa.
The tripod fish or tripod spiderfish, Bathypterois grallator, is a deep-sea benthic fish in the family Ipnopidae found at lower latitudes. It is now relatively well known from photographs and submersible observations, and seems to prefer to perch on the ooze using much elongated fin rays in the tail and two pelvic fins to stand, facing upstream with the pectoral fins turned forward so the outthrust projecting fin rays resemble multiple antennae, and are indeed used as tactile organs. B. grallator is hermaphroditic. At least 18 species are placed in the genus Bathypterois, several of which have similar appearance and behavior to B. grallator. B. grallator is the largest member of its genus, commonly exceeding a standard length of 30 cm (12 in) and reaching up to 43.4 cm (17.1 in).
The bigeye thresher is a species of thresher shark, family Alopiidae, found in temperate and tropical oceans worldwide. Like the other thresher sharks, nearly half its total length consists of the elongated upper lobe of the tail fin. Its common name comes from its enormous eyes, which are placed in keyhole-shaped sockets that allow them to be rotated upward. This species can also be distinguished by a pair of deep grooves on the top of its head, from which its scientific name is derived.
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.
The stoplight loosejaws are small, deep-sea dragonfishes of the genus Malacosteus, classified either within the subfamily Malacosteinae of the family Stomiidae, or in the separate family Malacosteidae. They are found worldwide, outside of the Arctic and Subantarctic, in the mesopelagic zone below a depth of 500 meters. This genus once contained three nominal species: M. niger, M. choristodactylus, and M. danae, with the validity of the latter two species being challenged by different authors at various times. In 2007, Kenaley examined over 450 stoplight loosejaw specimens and revised the genus to contain two species, M. niger and the new M. australis.
The abyssal grenadier, Coryphaenoides armatus, is an abyssal fish of the genus Coryphaenoides, found in all the world's oceans, at depths between 800 and 4,000 metres. Its adult length is 20 to 40 centimetres, although Fishbase gives lengths up to 1 metre. The abyssal grenadier's body is unique in that it contains two dorsal spines and about 124 dorsal soft rays, which are the flexible jointed rays supporting a fin nearest to the back in the spinal column. It has no anal spines, but has 115 anal soft rays along its body. The head and eyes of this fish are very large, while the mouth is very small. The color of the abyssal grenadier is brown apart from the abdomen, which is bluish.
The Portuguese dogfish or Portuguese shark, is a species of sleeper shark of the family Somniosidae. This globally distributed species has been reported down to a depth of 3,675 m (12,057 ft), making it the deepest-living shark known. It inhabits lower continental slopes and abyssal plains, usually staying near the bottom. Stocky and dark brown in color, the Portuguese dogfish can be distinguished from similar-looking species by the small spines in front of its dorsal fins. Its dermal denticles are also unusual, resembling the scales of a bony fish. This species typically reaches 0.9–1 m (3.0–3.3 ft) in length; sharks in the Mediterranean Sea are much smaller and have distinct depth and food preferences.
A blind fish is a fish without functional eyes. Most blind fish species are found in dark habitats such as the deep ocean, deep river channels and underground.
Gigantactis is a genus of marine ray-finned fish belonging to the family Gigantactinidae, the whipnose anglers. The fishes in this genus have a circumglobal distribution in the deep waters of the tropical and temperate zones of the Atlantic, Indian and Pacific Oceans.
Abyssobrotula galatheae is a species of cusk eel in the family Ophidiidae. It is the deepest-living fish known; one specimen, trawled from a depth of 8,370 m (27,460 ft) in the Puerto Rico Trench in 1970, holds the record for the deepest fish ever captured. Although generally recognized, some have suggested that the record-breaking individual might have been caught with a non-closing net and therefore perhaps caught shallower.
Thaumatichthys, the wonderfish, is a genus of deep-sea anglerfish in the family Thaumatichthyidae, with three known species. Its scientific name means "wonder-fish" in Greek; oceanographer Anton Bruun described these fishes as "altogether one of the oddest creatures in the teeming variety of the fish world." In contrast to other anglerfishes, the bioluminescent lure of Thaumatichthys is located inside its cavernous mouth. They are worldwide in distribution and are ambush predators living near the ocean floor.
The humpback anglerfish is a species of black seadevil in the family of Melanocetidae, which means "black whale" in Greek. The species is named after James Yate Johnson, the English naturalist who discovered the first specimen in Madeira in 1863. The common names include anglerfish, viperfish and fangtoothfish.
Scyliorhinus meadi, the blotched catshark, is a little-known species of catshark, and part of the family Scyliorhinidae, found in the western central Atlantic Ocean. It inhabits banks of deep-sea coral at depths of 329–548 m (1,079–1,798 ft), feeding on cephalopods, shrimp, and bony fishes. This species can be identified by its wide body and head, and the dark saddle-like markings on its back. It also has small spots that fluoresce yellow under a blue light. Adult blotched catsharks have not been observed; the largest immature specimen is 49 cm (19 in) long. Like other catsharks, it is believed to be oviparous. This species is not dangerous to humans and has no commercial significance.
Bathypterois is a genus of deepsea tripod fishes. They are a diverse genus that belong to the greater family Ipnopidae and order Aulopiformes. They are distinguished by having two elongated pelvic fins and an elongated caudal fin, which allow them to move and stand on the ocean floor, much like a tripod, hence the common name. Bathypterois are distributed worldwide with some particular species of the genus having specialized environmental niches, such as lower dissolved oxygen concentrations. Bathypterois have a reduced eye size, highly specified extended fins, and a mouth adapted to filter feeding. They are filter feeders whose main food source is benthopelagic planktonic calanoid copepods, but some variation is seen with maturity in secondary food sources. Bathypterois use their three elongated fins for a wide range of motion from landing to standing on the ocean floor to catching prey, for which these fins serve as specialized perceptory organs. Bathypterois have both male and female gonads at once making, them simultaneous hermaphrodites, whose gonads go through five stages of development following seasonal autumn spawning.
Himantolophus groenlandicus, the Atlantic footballfish or Atlantic football-fish, is a species of marine ray-finned fish belonging to the family Himantolophidae, the footballfishes. This fish is found primarily in mesopelagic depths of the ocean. Despite its name, this species might not be restricted to the Atlantic Ocean, with its range possibly extending into the Indian Ocean and to the Pacific Ocean. It is found in tropical and temperate regions.
Melanocetus murrayi, commonly known as Murray's abyssal anglerfish, is a deep sea anglerfish in the family Melanocetidae, found in tropical to temperate parts of the world's oceans at depths down to over 2,000 m (6,600 ft). Its length is up to 13.5 cm (5 in) for females and up to 2.8 cm (1.1 in) for males.
Ipnops meadi, also known as the grideye fish, is a highly specialized species of Placodithyran abyssal fish found in the Clarion-Clipperton Zone of the Indo-Pacific Ocean. The species was named after Giles W. Mead of the Harvard Museum of Comparative Zoology, a biology professor at Harvard, deep sea explorer, and ichthyologist.
Opisthoteuthis calypso or calypso flapjack octopus is a species of genus Opisthoteuthis, which are known as the cirrate octopuses. Octopuses in this genus are known as the flapjack octopuses and can be found in a variety of oceans across the world.
