Bathylagichthys Bathylagoides Bathylagus Dolicholagus Leuroglossus Lipolagus Melanolagus Pseudobathylagus The deep-sea smelts are any members of the family Bathylagidae, a distinct group of marine smelts.

Deep-sea smelts are marine fishes found in deep waters throughout the oceans, down to 1,500 m (4,900 ft) in depth.

They are small fishes, growing up to 25 cm (9.8 in) long.

Extinct genera known only from fossil remains include Quaesita from California, USA and Krumvirichthys from the Czech Republic.

The oldest fossils are otoliths from the Maastrichtian.