NUÑEZ OTAÑO Noelia Betiana
congresos y reuniones científicas
Cliteropenis morphology of hatclings and juveniles Caiman latirostris
NUÑEZ OTAÑO, NOELIA BETIANA; IMHOF, A.; BOLCATTO P.; LARRIERA ALEJANDRO
Congreso; VIII Congreso Latinoamericano de Herpetologia; 2008
We study the cliteropenis (CTP) morphology of Caiman latirostris, a species with temperature sex determination. We used 19 hatchlings coming from eggs incubated at 30°C and 33°C, with the aim to ensure that males and females will be available. In order to determine positively the sex of the animals, we inspectioned by direct observation the gonads after the sacrifice. CTP measurements were: Total Length, Lateral width and Head width. This structure are single medial organs and the body develops on the ventral wall of the cloaca, both penis and clitoris protrude from the cloaca in early embryonic stages but disappear into it, sometime before the hatch moment. We found significant differences between sexes in lateral width of CTP (p < 0,01) and head width of CTP (p < 0,01). From this results and other analysis, we developed a preliminary protocol that allow the discrimination of sexes based on the differences of the CTP measurements of C. latirostris at piping moment. The conclusion of this research is that based on simple morphometric measures of hatchlings, it is possible to sex them with a confidence of 89,4 %. On the other hand, additional information it is now obtained from juveniles of 24 months old reared in captivity, were the sex was diagnosed by cloacal examination of the live animal, holding them and exposing the CTP by separation of the cloaca with forceps. Animals were classified as males and females based on the relative size, shape and color of the CTP. As the animals utilized for this part of the experiment comes from a commercial operation, and they are regularly abated at this age, we also had the chance to confirm the gonadal sex of each animal, comparing then the results with the previous determination based on cloacal examination of the live caymans.