It is found in elasmobranchs (sharks, rays, and skates), seabirds, and some reptiles. Moreover, it is the only dinoflagellate capable of infecting teleosts and elasmobranchs . As is characteristic of elasmobranchs, batoids undergo internal fertilization. Some angel sharks have deformities that have been described in elasmobranchs. "S. canicula" is one of the most abundant elasmobranchs in the northeast Atlantic and Mediterranean. He was a world-renowned expert on coelenterates and elasmobranchs. In some elasmobranchs, only the right ovary develops fully. Larger elasmobranchs, such as hammerhead sharks, prey on the bluespotted stingray. As with all elasmobranchs, these teeth fall out and are replaced continuously. According to Tye, teleost fish feel pain but elasmobranchs and insects do not. Some of these studies have investigated personality in mammals, elasmobranchs, reptiles, fish and birds. Many fish inhabited the Carboniferous seas; predominantly Elasmobranchs (sharks and their relatives). Catches have declined and elasmobranchs are increasingly targeted by sports fishers. The second group contains elasmobranchs that only lives in freshwater environment their entire life. This evolutionary development does not account for the gland in elasmobranchs, suggesting convergent evolution.