Dusky smooth-hound fishes is their ability to continually replace the teeth in their upper and lower jaws. Smooth dogfish differ from other sharks because of their 10 rows of flat, blunt teeth. The teeth in the upper and lower jaws are similar in size and are asymmetrical with rounded cusps. These teeth are used to crush and grind food, rather than bite it. Their unique dentition is important for their crustacean-based diet. In smooth dogfish, tooth replacement is related to body growth. They grow about 10 cm per every six rows of teeth replaced. That is an increase of 0.03 mm per
Humpback smooth-hound 45°S. Its depth range is between but it is most common between . It is found near the seabed, often on rocky shores, where it feeds on small fish and crustaceans such as crabs and mantis shrimps. It is viviparous and the females bear litters of five to ten young which are about long when born. The humpback smooth-hound is fished for human consumption in Chile but more particularly in Peru, where it is more common. Along with the spotted houndshark ("Triakis maculata") and the speckled smooth-hound ("Mustelus mento") it is known as "tollo" in its local fisheries, and of