The courtship and mating behavior of the round stingray, Urolophus halleri

Abstract

Biting has been observed to be an important component of male mating behavior in several elasmobranch species. I observed male biting during courtship and mating in a population of Urolophus halleri, the round stingray, in the Sea of Cortez. Females allow males to bite the posterior and medial edge of their pectoral fin during courtship yet often appear to struggle to dislodge the male after they have been bitten. During mating the male bites the anterior edge of the females' pectoral fin and the female is passive. In response to this biting behavior females have relatively thicker discs than males and males have sexually dimorphic dentition. Larger adult males have relatively smaller yet more sharply curved teeth than smaller males that may allow them to hold on to females better during courtship. Therefore there is the potential for assortative mating based on male dentition and his ability to hold a female.