Need some help with new tile starfish

[Joesvwbora]

Hello all I picked up a Tile starfish on Thursday and today I noticed some damage to two of its legs. The only inhabitants that could have do anything is an emerald crab and blue leg hermit. Also how would I go about treating the wounded legs.
My water perimeters are
Nitrate 0ppm
Nitrite 0ppm
Alkalinity 250ppm
Ph. 7.8

Thank you

 

[Calappidae]

It's melting.

Red tile stars are fromias that ONLY eat invisible film algae and I think some kind of sponge as well.. They are best suited in large displays that are very well established of over a year atleast. Lot of people also complain they're flat out impossible but I've heard success stories and my red fromia lasted awhile until I moved it.

 

[olemiss reb]

My money is on acclimation shock-- irreversible. You're spot on the benthic microfauna but dropping legs is generally the first indicator that it is starving.