Due to the depth of their oceanic habitat, little is known about the natural ecology of this species. The young develop inside their mother (ovovivipary) and are attached to the outside of a yolk-filled egg of about 100 millimetres in diameter. The developing fish have this sac connected to their fore-belly region and as the yolk volume decreases and the embryo develops, the sac diminishes in size until it disappears completely. Shortly before birth the scar where the yolk was attached closes and heals completely (9). The mother then gives birth to as many as 26 live pups (3). These fish are very long-lived and some scientists believe them to live as long as 80 years (3). They appear to be most active at night, spending the day hovering in submarine caves and foraging along the coast at night (3). Individuals observed in the wild appear to occasionally swim with their heads down in a 'headstand' posture, but this is possibly a result of the light or electromagnetic field produced by the submarine (9). They are opportunistic drift-feeders, preying mainly on fish, including lantern and cardinal fish, eels, skates and many more (2).