The present study represented a contribution to the knowledge of the cytological and histological aspects of decapods' reproductive system, describing male germ cells of the spiny lobster Panulirus laevicauda. Seventy-one specimens of different sizes were caught off Fortaleza (Ceará, Brazil). Their testes were removed and fixed in Bouin solution, then, after 24 hours, dehydrated, cleared and embedded in the paraffin. Sections (4 µm thick) were stained with hematoxylin-eosin. The testes appeared macroscopically as a pair of long and highly convoluted tubes joined by a transversal commissure giving the organ an H-like shape. Microscopically, supporting cells and germ cells (spermatogonia I and II, spermatocytes, spermatids and spermatozoa) were seen in the testicular acini. Some of the acini showed signs of the spermotocytes and the spermatogonia degeneration. The spermatozoa were small cells with the peripheral nuclei and a lightly basophilic cytoplasm. They were nonmotile gametes and are characterized by the absence of a flagellum, but they had spikes radiating from the body. Three stages of follicular development in the mature individuals were observed: (a) predominance of spermatogonia I and II; (b) increasing numbers of spermatocytes I and II; and (c) spermatocytes I and II were prevalent. All the three stages of the spermatozoa were observed in the follicular lumen. These observations agreed with the published descriptions of other palinurid and homarid lobsters. A histochemical analysis of the testes showed that the main component of the tunic was collagenous fibers, that the seminal fluid contained plenty of glycoproteins and carboxyl-glycoconjugates and that the spherical bodies and spermatozoa contained glycoproteins and mucoproteins.
Histology; male reproductive system; spiny lobster; Panulirus laevicauda
