Humpback smooth-hound the lower ones. The teeth have a main pointed cusp and sometimes smaller subsidiary ones. The first dorsal fin is approximately triangular and the trailing edge is fringed with bare, dark-coloured collagen rods known as ceratotrichia. The pectoral fins are large and the pelvic fins moderately so. The caudal peduncle is short and the lower lobe of the tail fin is hardly curved in adults. The colour of this shark is plain grey or greyish-brown without any spots or barring. The humpback smooth-hound is found in the eastern Pacific Ocean off the coast of Peru and Chile, between 1°N and
Slender smooth-hound may also receive secondary nutrition in the form of histotroph ("uterine milk") produced by the mother. When the embryo is long, it emerges from the capsule, which by that time has become translucent and gelatinous. Embryos long have well-developed external gill filaments. The external yolk sac is entirely absorbed when the embryo is long and close to being born. Males and females reach sexual maturity at approximately long. Harmless to humans and of no economic value, the slender smooth-hound is occasionally caught incidentally in bottom trawls and on bottom longlines. Much of its northern range lies in little-fished waters, and