Feeds on wide variety of prey items. Soupfins have been described as benthic blue sharks. They are known to feed on squid, sardines anchovies as well as flat fish like sand-dabs and halibut. Soupfins appear to move north in the summer and southerly in the fall and winter but this is very tentative. In the north males are more abundant throughout the year while females are predominant in the south.
Reproductive development is oviparous.
Males are believed to mature at approx. Some mating is known to take place in the spring and gestation is believed to be about 12 months. Pups are born around 1 foot in length. Litters can range from 6 to 50 pups with the average being 25 to 30. While most of the nursery areas are believed to be south of Pt conception there are important nursery areas in the San Francisco, Humbolt and Tomales bays.