Testis Structure and Formation of Spermatophores in the Atherinomorph Teleost Horaichthys setnai

cells following spermiation. However, extreme modification is evidenced by its unusual bulblike shape and the formation of spermatophores within the germinal cyst prior to spermiation. The spermatophore capsule is produced by Sertoli cell secretions into the germinal cyst after germ cell maturation is completed. As in other teleosts, boundary cells do not form a complete layer over the tubule surface but, along with Leydig cells and blood vessels, reside within the extravascular space. It is proposed that the tubule basal lamina is a structural component of the testis.