Abnormal hermaphroditism in Pellona flavipinnis (Pristigasteridae: Clupeiformes).

This study records the occurrence of a hermaphrodite individual of the apapá Pellona flavipinnis captured in a floodplain area of the Amazon River. Histology of the left gonad revealed the presence of testicular germ cells (spermatocytes and spermatozoa) in the cranial portion and mature ovarian cells (primary and vitellogenic oocytes) in the caudal portion, separated by connective tissue. This is the first record of a hermaphrodite fish of the family Pristigasteridae, order Clupeiformes.