The viper fish

Any species of marine fish in the genus Chauliodus is referred to as a viperfish. The mesopelagic zone is the primary habitat of viperfish, which are distinguished by their long, needle-like teeth and movable lower jaws. An average viperfish can reach lengths of 30 cm. The world's tropical and temperate oceans are home to viperfishes, which migrate vertically every day. In order to blend in with the less than 1% of the light that travels below 200 meters of depth, viperfishes have photophores along the ventral side of their bodies.

Viperfishes inhabit meso- and bathypelagic settings, which are difficult for humans to directly see. Viperfish travel vertically throughout the day, moving up into more fruitful areas at night to feed. Due to their slow metabolism, or the fact that they probably do not need to eat every night, it is possible that only a portion of the entire viperfish population engages in diel vertical migration on any one night.

Depending on the species, viperfishes eat crustaceans and other pelagic fish. Lanternfish, bristlemouths, copepods, and krill have all been discovered in the stomachs of captured individuals.