Slender smooth-hound variety of benthic fishes and invertebrates, and also scavenges; human garbage has been reported among its stomach contents. Small bony fishes, lanternfishes in particular, are the most important prey type, followed by decapod crustaceans. Cephalopods, gastropods, isopods, brittle stars, dogfish sharks, and cartilaginous fish egg capsules may also be consumed. On the Challenger Plateau, cephalopods are an important food source for juveniles under long. Like the false catshark, the slender smooth-hound exhibits aplacental viviparity with oophagy, in a form different from that in the mackerel sharks. Mature females have a single functional ovary, on the right side, and two functional
Slender smooth-hound pups, one per uterus. The International Union for Conservation of Nature (IUCN) has assessed the slender smooth-hound as Least Concern; it is taken as fishery bycatch but not in great numbers, and furthermore large portions of its range see minimal fishing activity. The first known specimen of the slender smooth-hound was a long adult male collected by the trawler "Maimai" in December 1953, at a depth of off Cape Palliser on New Zealand's North Island. It was preserved by the crew as a curiosity and given to ichthyologist Jack Garrick, who described it in a 1954 issue of the scientific