Body and testicular biometric parameters of the scorpion mud turtle (Kinosternon scorpioides)

The reptile Kinosternon scorpioides is a freshwater chelonian, popularly known as jurara, and is found in the Baixada Maranhense, Maranhao State, Brazil. Due to the lack of scientific information on the reproductive biology of the species, current paper describes the body and testicular biometry and the gonad-somatic index (GSI) in adult specimens collected from the natural environment. Twenty male adults were collected in the rainy (n = 10) and dry (n = 10) seasons. Data were derived from the body, testis size and GSI and tests of correlation between these measures were performed. The body biometrics of free-living Kinosternon scorpioides is similar to those found in other studies for adult animals bred in captivity. The body weight was higher in animals collected in the rainy season than that in animals collected in the dry season. The testis size presents variations among animals captured during the rainy and dry season, but the gonadossomatic index did not vary between different groups of animals. Further studies were suggested related to the levels of sexual steroid hormones and behavioral studies to understand the factors related to the species's reproductive cycle. Keywords: chelonian, gonad-somatic index, Kinosternon, reptiles, testicular morphometric. O reptil Kinosternon scorpioides e um quelonio de agua doce popularmente conhecido como jurara, encontrado na Baixada Maranhense, Maranhao, Brasil. Diante da carencia de informacoes cientificas sobre a biologia reprodutiva desta especie, objetivamos descrever a biometria testicular e corporal, assim como, e o indice gonadossomatico (IGS), em especimes adultos provenientes de habitat natural. Utilizamos 20 individuos machos adultos, coletados no periodo chuvoso (n = 10) e periodo seco (n = 10), dos quais extraimos informacoes da biometria corporea e testicular, assim como o indice gonadossomatico e testes de correlacao entre estas medidas. Encontramos que a biometria corporea de Kinosternon scorpioides de vida livre e semelhante ao encontrado em outros estudos com animais adultos criados em cativeiro. No entanto, o peso corporeo foi maior em animais coletados no periodo chuvoso que o encontrado em animais coletados no periodo seco. A biometria testicular apresenta variacoes entre os animais de periodo chuvoso e seco, no entanto os indices gonadossomaticos nao variaram entre os animais dos diferentes grupos, portanto sugerimos estudos relacionados a niveis de hormonios esteroides sexuais e estudos comp