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
Speckled smooth-hound by artisan fishermen using gill nets. Landings in Chile peaked in 1989 at around 1300 tons but have since dwindled to less than 200 tons a year, with fish stocks declining and a transfer of the fisheries to targeting rays. In 2001, the Peruvian authorities introduced a minimum size requirement of for tollo. The speckled smooth-hound is assessed by the IUCN as being "near threatened" on the basis of its past over-fishing. This assessment may be raised to a more-threatened category if intensive fishing resumes. Speckled smooth-hound The speckled smooth-hound ("Mustelus mento") is a houndshark of the family Triakidae. It