Ophidiids

Ophidiids are a family of ray-finned fish, commonly known as cusk-eels. They belong to the order Ophidiiformes and are characterized by their elongated, often eel-like bodies, with dorsal and anal fins that are usually confluent with the caudal fin. Many species have a reduced or absent pelvic fin, which is typically located ventrally. Their coloration can vary widely, from drab browns and grays to more vibrant hues, and some species possess bioluminescent capabilities.

Ophidiids are found in marine environments worldwide, inhabiting a broad range of depths from shallow coastal waters to the abyss. They occupy diverse habitats, including coral reefs, rocky substrates, and the open ocean floor. Their diet typically consists of invertebrates such as crustaceans and mollusks, though some species may also consume small fish. Reproduction in ophidiids varies, with some species being oviparous (egg-laying) and others viviparous (giving birth to live young).

This family encompasses a significant number of species, many of which remain poorly understood due to their deep-sea habitats. Notable examples include species of the genus Genypterus, found in the southern oceans, and various species inhabiting the deep-sea trenches. Their ecological role often involves contributing to the benthic food web.