Gross and Microscopic Structures of the Male Reproductive System in the Whip-tail Stingray (Dasyatis bleekeri)

Abstract

The male reproductive organs of whip-tail stingray (Dasyatis bleekeri) were grossly observed and found that testes were paired and embeded in the epigonal organs. Each testis was composed of many lobes which supported by connective tissue. The average length, width and thickness of testis were 7.5, 3.5 and 1.7 cm., respectively. Microscopic study showed that the unit structure of testicular lobe was spherical ampulla. In each ampulla contained the developing spermatogenic cells of the same stage. The interstitial cells were also found between the ampulae. The testicular lobes were zonately arranged, each zone consisted of ampullae, again, all at the same stage of spermatogenesis. The ampullae were originated in the ampullogenic zone and later developed into the following forms of spermatogonial ampulla, primary spermatocyte ampulla, secondary spermatocyte ampulla, spermatid ampulla, spermatozoal ampulla and finally became empty ampulla. Spermatozoa were released from testis into vas efferent, epididymis, vas deferens and seminal vesicles, respectively.