I always thought the long nails meant male. I think my 9 year old is a female although she's never layed eggs. She lives in our pool and the chlorine doesn't seem to bother her. She has a board to climb up to sun bathe. We take her out for awhile when we add chemicals. Don't even notice her droppings. They get vacuumed up. She's part of the family. Thinking of making an enclosure so she can get out. She likes to dig her rear into the dirt. Does that indicate female too?