The spermatogenesis, including the spermiogenesis, in Urodeles contains the meiotic process and the morphological differentiation of the spermatids developing the spermatozoa as in the rest of vertebrates. However, in Urodeles, there are essential differences in the structure of the testis, as a lobular structure; the distribution of the spermatogenic cells, in cephalocaudal progression in the testis; and the cystic condition of the developing spermatogenic cells in synchronous groups bounded by Sertoli cells. All the spermatogenic cells are situated in parallel position with the heads directed to the same side. The big size and elongated morphology of the spermatozoa also characterized this type of spermiogenesis. Spermiation occurs at the caudal portion of the testis to the efferent duct system, which includes the mesonephric nephrones
