Sex Differences in the Genitalia of Hatchling Caiman latirostris

NOELIA B. NUÑEZ OTAÑO, ALBA IMHOF, PABLO G. BOLCATTO AND ALEJANDRO LARRIERA

HERPETOLOGICAL REVIEW

Society for the Study of Amphibians and Reptiles

Año: 2010 vol. 41 p. 32 - 35

0018-084X

We study the cliteropenis (CTP’s) morphology of Caiman latirostris, a species with temperature sex determination. We used 19 hatchlings which eggs were incubated at 30 ºC and 33 ºC, with the aim of ensure that males and females will be availables. In order to determine positively the sex of the animals, we inspectioned by direct observation the gonads after the sacrifice. CTP’s 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 (α=0,05) 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’s 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 %.