Common smooth-hound on its underneath. It is often confused with the starry smooth-hound which has white spots on its back. The starry smooth-hound can often have faded spots which leads to misidentification. Another shark it is often confused with is the tope shark although the common smooth hound has a larger second dorsal fin. Due to the similarities between the common smooth-hound and other sharks, misidentification occurred for a long time. The common smooth-hound has two dorsal fins, an anal fin, a pair of pectoral fins, a pair of pelvic fins and a heterocercal tail. All of these fins help stabilise the
Slender smooth-hound in size. The diet of the slender smooth-hound is diverse, but dominated by small, benthic bony fishes and decapod crustaceans. It exhibits a specialized form of aplacental viviparity with oophagy: the females produce a single capsule in each uterus that contains 30–80 ova, of which one ovum develops into an embryo that consumes the rest of the ova and stores the yolk material in its external yolk sac. The growing embryo is mainly sustained by this yolk sac during gestation, though it may be additionally supplied with histotroph ("uterine milk") produced by the mother. The typical litter size is two