True Hermaphroditism: First Evidence of an Ovotestis in a Cetacean Species

An immature unilateral hermaphrodite common dolphin (Delphinus delphis) was found stranded on the southwest coast of the UK. The external phenotype was that of a female, but internally there was one ovotestis, containing both ovarian follicles and testicular tubular elements, and a contralateral ovary. Ovarian portions of the ovotestis appeared normal and demonstrated follicular development, whereas the testicular tissue exhibited hypoplasia and degeneration. This is the first reported case of an ovotestis in a cetacean species.