Morfometria de testículos y celulas germinales de Allobates femoralis (Boulenger 1883) (Dendrobatidae: Anura: Amphibia)

Abstract

The present study describes the morphological aspects of the testis and presents a general characterization of the seminiferous elements of adult specimens (N=8) of Allobates femoralis (Boulenger, 1883) collected at the Panguana Biological Station (9°37'S 74°56'W), 250 masl, upstream of the Pachitea river, Yuyapichis district, Puerto Inca province, Huanuco, Peru. The amphibians (25.99 ± 0.97 mm in length) were dissected and their testes were isolated for macroscopic descriptions; later, routine histological protocols for microscopic analysis were done, colored with hematoxylin and eosin dye. The germinal stages were described and measured with the help of an ocular micrometer. The biometrics of the testes were: major axis = 2.254 mm (SD=0.282), minor axis = 1.343 mm (SD=0.181), width = 0.971 (SD=0.097). At a microscopic level we found the albuginea coat (6.51 ± 1.74 im width) formed by connective tissue and smooth muscle. The seminiferous tubules (162.56 ± 47.61im) were delimited by a thin layer of connective tissue. Regarding the microscopic features, spermatogenesis in A. femoralis occurs into the seminiferous tubules where the cellular elements are organized in spermatocysts. Each cyst contains cells in the same stage of development. The characterization of each cell type allowed the identification of the germ line cells: 1) Spermatogonia, isolated cells or forming groups of the most voluminous cells of the germinal linage (7.07 ± 1.187 im) with an irregular nucleus shape. They laid very close to the seminiferous tubule. 2) Spermatocyte I, with a smaller form than spermatogonias (6.95 ± 1.21 im). 3) Spermatids; with a round shape, as they advance in their development, they elongated slightly and are organized into bundles whose heads are attached between them. 4) Spermatozoa, elongated with the flagellum lightly stained, are well compacted cells with the nucleus and cytoplasm reduced, elongated and extend into the lumen of the seminiferous tubule. It is reported for the first time the macroscopic and microscopic description of the testis of A. femoralis in Peru.