Desenvolvimento do olho e diferenciação da retina em peixes Betta splendens Regan, 1909

Abstract

The present study it aimed at to describe the ocular development, with emphasis in the retina of the Betta splendens fish, an ornamental fish that presents an extra-embryonic development, favoring research that involves one better agreement of its embryology and studies on degenerations and regenerations, ontogeny and differentiation occured in the eye, this research was carried through of the embryonic period up to ten days post-eclosão. The complete development of the eye when it has the eclosion of the animal. For the study of the stages of development the animals had been anesthetized in water with Eugenol 50ppm, were fixed in a solution of 4% paraformaldehyde in phosphate buffer, dehydrated and infiltrated with Paraplast Plus. After that, confectioned sections of 1-5μm of thickness and stained with HE, PAS and staining TUNEL. As result was possible to observe that the eyes had appeared of evaginações of diencéfalo, forming the optic cup. Neuroectoderm, the mesoderm and the ectoderm of the surface are involved in the formation of the eye. The staining TUNEL identified to process of apoptotic cells in the retina and lens, proving that it has a reduction of cells during the development of the animal. In the adult fish, through the chemistry it was possible to observe the morphology and the cellular arrangement of the photoreceptors.