Injured Serpent Starfish

[brothacraig75]

Hi, looking for some help regarding a serpent starfish that I just put in my fish-only 180g tank three days ago. Until this morning it was out of sight/out of mind amongst the live rock. This morning I found it in plain sight on some rock and still moving but with some serious damage to the disc and missing a leg. See pic below, any help would be great.

Current fish in tank:

False perc clowns
Pajama cardinals
A few assorted damsels
Green chromis
Yellow tang
Sailfin tang
Hippo
Purple kole tang
Gobey and blenny
Pistol shrimp
Blood shrimp
Cleaner shrimp
Plenty of snails/hermits


Thanks