Marine hatchetfishes or deep-sea hatchetfishes are small deep-sea mesopelagic ray-finned fish of the stomiiform subfamily Sternoptychinae. They should not be confused with the freshwater hatchetfishes, which are not particularly closely related Teleostei in the characiform family Gasteropelecidae.
Polyipnus is a genus of oceanic ray-finned fish in the family Sternoptychidae. This is the largest genus of the marine hatchetfishes subfamily Sternoptychinae and indeed of the entire Sternoptychidae. It is not quite as apomorphic as their relatives; it may be that the genus is actually a paraphyletic assemblage of less advanced Sternoptychinae and would need to be split.
Max Fernand Leon Poll was a Belgian ichthyologist who specialised in the Cichlidae. In the years 1946 and 1947 he organised an expedition to Lake Tanganyika.
Xiphasia matsubarai, the Japanese snake blenny, is a species of combtooth blenny found in the western Pacific and Indian oceans just extending into the Atlantic Ocean in False Bay, South Africa. This species can be found at depths ranging from the surface to 4,960 m (16,270 ft). This species reaches 30 cm (12 in) in SL. This species feeds primarily on bony fish, rising to the surface at night to feed. It can also be found in the aquarium trade.
Polyipnus clarus, commonly known as the stareye hatchetfish or slope hatchetfish, is a species of ray-finned fish in the family Sternoptychidae. It occurs in deep water in the western Atlantic Ocean from the Gulf of Maine southward to the Caribbean Sea and the Gulf of Mexico. It most commonly occurs between 300 and 400 metres but can range from 40 and 830 metres.
Polyipnus nuttingi, commonly known as Nutting's hatchet fish, is a species of ray-finned fish in the family Sternoptychidae. It occurs in deep water in the Indo-Pacific Ocean, at depths between about 384 and 658 metres.
Polyipnus spinosus, commonly known as the spiny hatchetfish, is a species of ray-finned fish in the family Sternoptychidae. It occurs in deep water in the western central Pacific Ocean, at depths down to about 500 metres (1,600 ft).
Polyipnus stereope is a species of ray-finned fish in the family Sternoptychidae. It occurs in deep water in the northwestern Pacific Ocean, at depths between about 150 and 280 metres.
Polyipnus triphanos, commonly known as the threelight hatchetfish, is a species of ray-finned fish in the family Sternoptychidae. It occurs in deep water in the Indo-Pacific Ocean, at depths between about 322 and 966 metres.
Polyipnus tridentifer, commonly known as the three-spined hatchetfish, is a species of ray-finned fish in the family Sternoptychidae. It occurs in deep water in the Indo-Pacific Ocean, at depths between about 640 and 825 metres.
Polyipnus latirastrus, commonly known as the combside hatchetfish, is a species of ray-finned fish in the family Sternoptychidae. It occurs in deep water in the western Pacific Ocean, at depths between about 696 and 888 metres.
Polyipnus polli, commonly known as the round hatchetfish, is a species of ray-finned fish in the family Sternoptychidae. It occurs in deep water in the eastern Atlantic Ocean, at depths between about 250 and 600 metres.
Polyipnus elongatus is a species of ray-finned fish in the family Sternoptychidae. It can be found in deep water in the southwestern Pacific Ocean around Australia, at depths down to about 400 metres (1,300 ft).
Polyipnus kiwiensis, commonly known as the kiwi hatchetfish, is a species of ray-finned fish in the genus Polyipnus. They live in the Tasman Sea off Australia and New Zealand. They are carnivores.
Polyipnus danae is a species of ray-finned fish in the genus Polyipnus. It is found in the South China Sea in waters from 0 - 700 meters.
Polyipnus omphus is a species of ray-finned fish in the genus Polyipnus. It is found in the Western and Central Pacific and lives below 200 m.
Polyipnus fraseri is a species of ray-finned fish in the genus Polyipnus. It is found in the Western Pacific Ocean.
Polyipnus laternatus is a species of ray-finned fish in the genus Polyipnus. It is found throughout the Caribbean Sea and the Gulf of Mexico in waters from 370 - 500 meters.
Polyipnus meteori is a species of ray-finned fish in the genus Polyipnus found in the Indian and Pacific Oceans.
Polyipnus paxtoni is a species of ray-finned fish in the genus Polyipnus found in the Western Central Pacific between depths of 0 and 300 meters.
