Testicular morphology of tuvira (Gymnotus spp.) submitted to reproduction by different hormones inducers

Abstract

The aim of study was to analyze the testis morphology of males tuviras (Gymnotus spp.) submitted to reproduction by different hormonal inducers. Forty male tuviras (40g ± 5.0) were used approximately in a completely randomized design with four treatments and 10 replicates; each animal was considered a repetition. For hormonal protocol establishment were tested three inducers: crude extract of carp pituitary (EBHC), equine chorionic gonadotropin (ECG), synthetic analogue of gonadotropin-releasing hormone (GnRH-a) and the control group was administered saline solution at 2%. The three hormones and control were applied in two doses (preparatory and final induction). Ten males per treatment were euthanized for macroscopic and microscopic analysis. It was determined volumetric proportion occupied by the components of testicular parenchyma (seminiferous tubules and intertubular tissue) and quantified populations of spermatogonia type A, type B, primary spermatocytes, secondary spermatocytes, spermatids, Sertoli cells (S) and lumen measurement . The results indicated that the hormone GnRH-a showed a higher capacity to promote the final maturation of the testes (P < 0.05), followed by eCG hormone. The EBHC hormone failed to promote the final maturation in males tuviras.