Caudal Spine Replacement and Histogenesis in the Round Stingray, Urobatis halleri

Abstract

Many stingray species replace their poisonous caudal spines season- ally; however, it is hypothesized that spine replacement may also be induced through a traumatic injury to the caudal spine. To determine whether the round stingray, Urobatis halleri, can replace damaged spines outside of normal spine shedding season, secondary spine growth of stingrays with clipped, removed, and intact primary spines was compared. Additional rays were separately collected for histological analysis of spine development. Though initial results indicated no difference in spine initiation among the treatments, later spine removals showed the ability of U. halleri to replace lost spines.