In a fish only aquarium, the specific gravity should fall between 1.020 and 1.023.Diet and Feeding: The Smooth Hound Shark are carnivorous and feed mainly on benthic invertebrates (worms, crabs, shrimp, and small shellfish), possibly also small fishes.Breeding: The gray smoothhound is viviparous, which means it gives birth to live young, usually during spring.