Gonadal cysts in spotted gar (Lepisosteus oculatus) from Bayou Trepagnier, Louisiana, USA

Gonadal cysts of spotted gar (Lepisosteus oculatus), an air-breathing teleost commonly found in Louisiana waters, are described. Fish were collected from two sites: Bayou Trepagnier, a petroleum-contaminated site (30 males and 42 females), and Bayou Traverse, a control site (17 males and 15 females). After fish were evaluated for gross abnormalities, they were necropsied and the gonads, gonadal ducts, and gonadal cysts were evaluated histologically. Multilocular fluid-filled cysts were noted in the testes, or spermatic ducts of four spotted gars from the Bayou Trepagnier. Unilateral ovarian cystadenomas were present in one female from Bayou Trepagnier. No cysts were observed in the gonads of spotted gar from the control site.