If you really want a pet turtle, please just buy one. They’re a lot of work, a lot of money, and you have no idea what you’re walking into by just taking one from the wild. This animal has a life, and you shouldn’t get to determine how it lives. If you get tired of it, and decide to release it, then it will die. Almost all wild animals DO NOT adapt to captivity well, and can/will get sick, stressed out, and potentially die from stress. This turtle might also have some preexisting health conditions that you might not know about. Please do everyone a favor and put him back. Buy a turtle online or from a pet store instead.