The testicular development in 31 Agoutis, of the Dasyprocta aguti species, from the birth up to 14 months of age was studied through the histometric analysis. Mid diameter and the mean area, in each testicle, were obtained through 30 crosscuts of the funiculus and/or the seminiferous tubule, by means of a computerized system for image analysis and a Zeiss CPL 10X ocular micrometric device, coupled to an objective lens of 40X. Testicles volume proportions were obtained through the stereometric method, according to Elias, Henning and Schwartz¹. Tubule medium diameter presented a slow growth from the birth to the eight months of age, for both used methodologies. When the ocular micrometric device was used it was observed that, beginning in the ninth month, the tubule diameter had an accelerated growth getting to duplicate its value if compared with the preceded age group. The volume proportion of the testicle cord and the seminiferous tubule grew gradually, reaching its maximum value (86,50%) on the ninth month. The Leydig cells presented a decreasing volume proportion, and their largest values were expressive from the birth up to four months of age (7,00 ± 1,77% to 9,55 ± 0,64%) and a minimum value, starting from nine months, still tending to stabilize. The stroma decreased with the development of age and fall abruptly when the puberty starts. It is concluded that the diameter of the testicles cords and seminiferous tubule presented a larger growth coinciding with the start of puberty and the volume proportion of the Leydig cells was lower in the same period.
Agouti; Postnatal development; Histometry; Testis; Seminiferous tubule
