Endoscopic Sexing of Juvenile Softshell Turtles, Amyda cartilaginea

Whilst the sex of offspring in most vertebrates depends on a genotypic sex determination (GSD, sex determined by maternal and paternal genes and/or sex chromosomes), temperature dependent sex determination (TSD) seems to be the most common form of sex determination in turtles. Most turtles have a prolonged juvenile phase and take many years or even decades before they reach maturity and can be sexed externally. However, in contrast the non-lethal sexing of juveniles is increasingly important in ecological studies and in conservation and recovery projects of threatened turtle species. Endoscopy is currently the only 100% accurate non-lethal method available to sex juvenile turtles that do not show external sexual dimorphism. Until now juvenile softshell turtles (family Trionychidae) have never been sexed with this method, probably because the currently accepted wisdom is that softshell turtles have GSD and not TSD.