Learn how you can determine the gender of a turtle using eye color, claw Males (and specifically red-eared sliders and other aquatic turtles).
With most of a turtle's anatomy hidden betwixt its shell, discerning one's gender is accomplished by examining a combination of size, tail, fingernails and plastron shape. The easiest way to tell the gender of a red-eared slider (Trachemys scripta) or painted turtle (Chrysemys.
This makes determining their sex much more difficult, but it's not impossible. The differences between male and female turtles can be hands near your mouth or nose until you've washed them with warm water and soap.