Histological structure of testicular and male genital ducts in siamese crocodiles (Crocodylus siamensis)

Five sets of testes and male genital ducts of Siamese crocodiles, aged 3-4 years were collected and processed by the histologic technique. The tissues were cut 5 micrometres thick and stained with H and E, PAS and Masson trichrome methods. The sections were observed under a light microscopic. The testes were surrounded by fibrous connective tissue, with the tunica albuginea and their septum separating the organs into lobules. The testes consisted of packed seminiferous tubules, the lumen of tubules consisted of various stages of spermatogenic and Sertoli cells. The latter were irregularly shaped with ovoidal or pyramidal nuclei and a prominent nucleolus. Among the tubules were Leydig cells, polygonally shaped and with a large round nucleus, prominent coarse chromatin granules and a nucleolus. Male genital ducts were divided into 5 regions, 1. Rete testis with simple squamous or cuboidal epithelium, 2. Ductuli efferentes with pseudostratified columnar epithelium, 3. Ductuli epididymides with simple columnar epithelium, 4. Ductus epididymidis with simple columnar epithelium and 5. Ductus deferens with pseudostratified columnar epithelium.