Abnormalities of the gonads of carp

Cyprinus curpio is usually dioecious, with well–developed paired gonads (ovaries or testes) of which the two parts are approximately equal in weight. However, a few instances of abnormal development have been observed. In one male fish, the right testis developed normally to maturity, while the left testis was vestigial. In a female fish, only the right component of the ovary was present. Some monoecious, synchronous hermaphrodite specimens have also been observed, and self fertilization demonstrated experimentally. It has been shown (Kossmann, 1971) that the progeny of such synchronous hermaphrodites may also have this characteristic. These studies demonstrate that even such a highly evolved teleost as the Carp may retain the primitive characteristic of hermaphroditism.