Tooth Replacement and Body Growth Rates in the Smooth Dogfish, Mustelus canis (Mitchill)

Tooth width growth increments per replacement tooth row were obtained for a series of Mustelus canis captured in Buzzards Bay, Massachusetts. The average increment was 0.03 mm in immature sharks. By relating tooth width to body length it was estimated that six tooth-row replacements occur in 10.0 cm of total length growth. Von Bertalanffy growth curves constructed from these data, although approximations at best, predict that smooth dogfish reach maturity in about one year and may reach maximum size in seven or eight years. Broken teeth in the functional series were found in 50% of the specimens examined. This finding is related to the necessity of rapid tooth replacement, even in sharks with a durophagous dentition.