ABSTRACT
In most teleosts, testes are paired elongated organs, attached to the dorsal wall of the body by a mesorchium. Both testes join caudally, converging in a central efferent duct system which is open to the exterior through the urogenital pore. The testes change morphologically during the annual reproductive cycle. Functions of teleost testes are basically conserved, as in other vertebrates, regarding three main aspects: 1) the formation of spermatozoa during spermatogenesis, 2) delivering them to the efferent ducts during spermiation, and 3) the secretion of male sex hormones (Pudney 1995).
