Morfologia das gônadas de ema (Rhea americana) em desenvolvimento: diferenciação sexual / Morphology of the gonads of rhea (Rhea americana) in development: sexual differentiation

ABSTRACT

The aim of this study was to evaluate the morphogenesis of rheas reproduction equipment featuringgonadal differentiation phase. We used eight fetuses, obtained from eggs, the Study Group Preservation of WildAnimals UFPI. The animals were fixed in formalin 5% 70% alcohol, dissected and analyzed bystereomicroscopy. Fragments of the urogenital organs were dehydrated in alcohol, diaphanized in xyleneemblocados and subjected to 5μm sections stained with hematoxylin-eosin. It was found in fetus 14 days theurogenital structures as two elongated bodies, dorsally in the coelomic cavity, lateral to the midline, andflattened dorsoventrally, the urogenital ridge; 18 days were divided medially, forming new ventral massprimitive gonads and a dorsal primitive kidneys; 21 days, were completely separated, the lobate kidneys andgonads with smooth surfaces and fetus of 30 days was observed the evolution of the development of the gonads.The rhea sexual differentiation phase occurs on the 14th day of fetal development.(AU)