change in behavior

Question
I have a small RES. I am in Austin, Texas.

The turtle was found by a student at our school who said that she found the turtle outside and that she had kept it for about a week.  The student's mom said that she could not keep the turtle anymore so she gave him to me.  I have kept him in our aquarium for about a  month now.  About two weeks ago, I bought a floating dock and a special light to bask.  

All seemed well.  Shell is hard.  Turtle is active and eating well.  His normal behavior is to swim often and bask a lot during the day.

Yesterday he looked like he was going to die.  Infrequent breathing, laying at the bottom of the tank without movement, etc.

I have read about symptoms of bad health and the turtle does of have any of these symptoms.

Could the little guy be trying to hibernate?  What do I do?

Thank you in advance for any help that you might giv eme.

Michael

Answer
A sudden change in health is a pretty bad sign in turtles. In this case, I'm thinking 'maladaptation'- the stress a turtle goes through when its habitat changes, commonly experienced by wild-caught turtles suddenly penned up.

The time-table works about right for this- it tends to hit nice and hard a few weeks after the capture.

Hibernation is triggered by temps and lighting. With good summer-like temps and lights it is not a big issue.

What I suggest at this point is either releasing it to a city park lagoon or other calm water near people (to minimize disease issues).

If this is not an option, review the care issues and diets at sites like http://www.redearslider.com or http://www.austinsturtlepage.com and see how your cares line up with their recommendations.