They are small, slender fishes, with maximum length ranging from about 10 to 40 cm (3.9 to 15.7 in).

They are found in temperate and tropical deep waters of the Atlantic, Indian, and Pacific Oceans.

A number of species, especially in the genus Bathypterois, have elongated pectoral and pelvic fins.

In the case of the tripodfish, Bathypterois grallator, these fins are three times as long as the body — up to a meter in length — and are used for standing on the sea floor.

[1] Ipnopidae is a species of fish that have adapted to living in the deep.