RESUMEN
Kinosternon scorpioides, popularly known as scorpion mud turtle (jurará in Brazil), is a fresh water species. There is little information about its reproduction and the present study aims to morphologically characterize the reproductive organs of male K.scorpioides bred in captivity in two seasons of the year. The reproductive tracts of adult animals under went macroscopic ultrastructural analysis of the lumen, as well as scanning electron and transmission microscopy. Macroscopically, the male genital organs consist of a pair of testicles, epididymis, the vas deferens and a penis. Testicles, epididymis and deferents ducts were characterized by reproductive activity during the rainy season and reproductive inactivity in the dry period. The morphometry regarding the tubular and luminal diameter and epithelial height of the testicles, epididymis and deferents ducts showed changes along the studied periods. The rainy season presented higher averages than the dry period. The penis did not show any changes during both periods. It was concluded that K. scorpioides exhibits reproductive seasonality.