What could be gnawing on my starfish

[Chirp]

I have a marble sea star in my tank and I just noticed that there were some bite marks on one of its arms. The other residents of my tank are:
1. Midas blenny
2. False clown
3. Pygmy dwarf angelfish
4. Royal gramma
5. Yasha goby
6. Mini pistol shrimp
7. Fire shrimp
8. Some hermit crabs
9. Some snails

Also a couples days prior, I saw that one of its arms was underneath its body. Do you think it's possible that the sea star gnawed on itself?

 

[Ajm]

I have a marble sea star in my tank and I just noticed that there were some bite marks on one of its arms. The other residents of my tank are:
1. Midas blenny
2. False clown
3. Pygmy dwarf angelfish
4. Royal gramma
5. Yasha goby
6. Mini pistol shrimp
7. Fire shrimp
8. Some hermit crabs
9. Some snails

Also a couples days prior, I saw that one of its arms was underneath its body. Do you think it's possible that the sea star gnawed on itself?

Could have been a shrimp maybe a crab. The same happened to my sand sifting star. He had a small piece of one of his arms missing its slowly growing back though. I suspect my cleaner shrimp. He was attacking one of my snails recently. Just keep an eye out for one of the inverts. And keep them well fed for sure.

 

[bioteacher]

I confused deterioration for bite marks at the beginning. Can you post a pic?

 

[Chirp]

I confused deterioration for bite marks at the beginning. Can you post a pic?

It's the arm on the left side. It doesn't look like it's deteriorating. It looks like chunks have been bitten off. Any idea who might have done it?

 

[Hocky puck]

Could be angel but my money's on hermitcrab

 

[markboote1978]

I had a sand sifting star and my tiger pistol destroyed it! I would watch it pick it up and snap at its legs... I reckon its your pistol matey.