Sex Determination
Many species of fishes are hermaphrodites. Some, such as the painted comber (Serranus scriba), are synchronous hermpahrodites. These fish have both ovaries and testes and can produce both eggs and sperm at the same time. Others are sequential hermaphrodites. These fishes start life as one sex and undergo a genetically programmed sex change at some point during development. Their gonads have both ovarian and testicular tissues, with one type of tissue predominant while the fish belongs to the corresponding gender.
Read more about this topic: Fish Development