So you may be embarking on a long commitment. You can usually tell the difference by looking at the animal s feet. Aquatic turtles have feet that are suited for swimming and have webbing between the toes. Others lack webbing and are strictly land turtles. In most turtles, you can tell the difference between a male and female because their tail length differs.
Males have a longer pointed tail than the females.
This is, of course, just a guideline. The shell has evolved for protection from predators. It has a bony structure and is actually made of ribs fused in such a way that they form a capsule around the animal. When a predator comes along, the turtle can retreat into its shell. Turtles adjust easily to confinement and we know that they have an acute sense of smell, and they can distinguish certain colors.