how big is it?
grab some raw shrimp, thaw one out and feed it to the star, put it in the tank and make sure he grabs it, he'll roll it up in his arm and take it to his mouth
if he's smakk cut the shrimp into a smaller piece, mine is about 7" tip to tip ans he eats whole medium shrimp, also try sinking pellets
Im afraid he may be too far gone now and wont start eating but we'll see
hand the shrimp directly to him, put it in his arm