This means that your turtle has a disease from lack of calcium in which its bones and shell start to deteriorate and weaken. You should keep its water shallow and make a dry bed of flat rocks or cork because it will not want to move much, also use a reptile light and an incandescent light and keep the water at about 78-82 degrees, I'm sorry to say that your turtle will probably die but if you follow this there's a slight possibility it will survive or at least you might ease its pain from dying this horrible death
