The genera and species of "Crocodile sharks"

A family with only one species, the crocodile shark, Pseudocarcharias kamoharai, is a very small species with very big eyes. Crocodile sharks do not possess nicitating membranes, have well developed gill slits and a long, spindle-shaped body. They have two spineless dorsal fins and weak keels on the peduncle with a precaudal pit in front of the caudal fin. The pectoral and dorsal fins are small. Crocodile sharks are abundant in epipelagic and possibly mesopelagic waters down to at least 300 m depth. The biology is not well known yet but their big eyes suggests nocturnal or deepwater activity, and possibly a diel pattern of movement toward the surface at night. It is assumed that crocodile sharks feed on small fishes. They show an ovoviviparous style of reproduction (aplacental viviparity) with an intra-uterine cannibalism.