Contributions to the knowledge of microscopic morphology of the gonads of Cuban amphibians and reptiles

Abstract

Introduction: The ecological importance of amphibians and reptiles, vital in the functioning of ecosystems and with diverse reproduction patterns, is recognized. There are not many studies in the biology of reproduction in Cuban species. The objective is to show the impact of histological and ultrastructural studies of the gonads of Cuban amphibians and reptiles in determining the reproductive status of the specimen and the stages of gametogenesis. Methods: Eleven frogs of the genus Eleutherodactylus, one hylid and eight toads of the genus Peltophryne were collected, in addition to three species of lizards; two lizards, a geckonid and five snakes. The gonads of both sexes were processed with classical histology, immunofluorescence, transmission electron microscopy, and atomic force microscopy. Results: In amphibians and reptiles, oocytes are classified as previtellogenic, vitellogenic and postvitellogenic, according to the process of synthesis and deposition of yolk. There is a greater number of vitellogenic oocytes in the reproductive stage. The testes contain seminiferous lobes in amphibians where cystic spermatogenesis takes place and tubules in reptiles, with radial spermatogenesis. Bidder's organ was identified in male and female toads. The morphology of sperm in amphibians is similar, even at the ultrastructural level, and different between lizards and snakes. Conclusions: classical histology establishes differences at the cellular level in ovaries and testes, an essential aspect to describe the gonadal cycles that occur in amphibians and reptiles. The histological and ultrastructural characters allowed to describe the cell types of gametogenesis.