Mits

I noticed that my black and white brittle star hasn't been as active as usual recently, and last night I noticed that one of his legs seemed like it had about a half inch piece missing when he was close to the glass. I was a bit worried, but today it got much, much worse. I saw what appear to be 1-2 inch long pieces of brittle star leg all over the tank, some still moving a bit. The main disc had one leg attached but it looked like the top had come open too. It was as if the whole star just fell apart. Could it be from starvation? I have been controlling my feeding more over the last few months, leaving the pumps on while feeding the fish to avoid a ton of uneaten food because of a GHA outbreak. There hasn't been as much food falling down to the bottom for him to go after but I thought he could find it anywhere. He was really aggressive about it in the past. Here are my parameters:

SG 1.025
Temp around 80
Alk 9.6 dkh
Ca 410
Mg 1410
Nitrate 0