DON'T CLIP THE TURTLE'S NAILS AS YOU WILL HURT HIM AND DRAW BLOOD you have a male slider it uses these long nails(the third and fourth) to entice the female(which have no long nails) in a courtship display where the male hovers over the female and shakes his arms over it's head.the longer tail also proves that it's a male
One Of My Turtle Has Really Long Nails And A Longer Tail Than The Other One. Is It Still A Red Ear Slider?
I think the length of the tail differentiates the male from the female (don't ask me which way round though!). Nail length depends on wear and tear, so for some reason this one is not using the front claws as much, you may need to clip them.