Sand Sifting Star... eroding?

[Corty]

I recently got a sand sifting star from my LFS. I had purchased a fish from them earlier that had HLLE, so I was extra careful to look at the star and make sure it had all its legs and seemed ok. It did, so I purchased and headed home.

I acclimated it over a little more than a couple of hours, and it took to the sand fairly quickly. He didn't seem to suffer from any sort of shock.

He's moved around a bit.. from one end of the 55 gallon to around the middle. He slowed down in the past day though.

I noticed his arm looked odd.. To my shock (I actually jumped a little), a part of his arm was missing. It wasn't the tip that was missing - it was part of the arm near the central disc. The inside of his arm is visible. Only a small amount is missing.. maybe three to four segments.. but still, not a good sign.

Amphipods (I think) are crawling into the hole, and running around and over him.. he doesn't seem to be reacting. He is in a different place from where I saw him last though, so apparently he's alive. Only fish in the tank is a tang. Only other inhabitants are turbo snails, hermit crabs, a serpent star (who is doing well, have had him for a couple of months now), and the two critters I just noticed tonight - a small red worm, and what looks almost like an anenome. I doubt they've done anything, however, as they're on opposite ends of the tank, and the starfish is in the middle.

None of the crabs have been picking at him, and when there's food or anything dies, they're usually *right there*.

I did a water test, and (I admit, I use the little quick strips) they said everthing was "ideal".

I've had him for about a week.

I tried to take a picture, but my camera can't get close up.

Can anyone help me out? I really don't want to lose my little buddy, nor do I want him to pass on an infection to my other star.

 

[quarryshark]

He shouldn't pass anything. At this point just keep your water quality pristine and leave him be. You could try and target a small piece of fish or shrimp, just place it beside or under him.
Thats all you can really do, I wouldn't move him or anything, would do more harm.
Good luck.

 

[Corty]

Update on the star: Leg is disappearing rapidly, several segments gone, and part of the inside from when I had checked on him before (couple of hours ago), but moving down, away from the central disc. I'm hoping it'll stay that way. There's still a very small piece of leg between the disc and the problem. It's about two segments long. Star is moving around again, apparently not noticing the leg (or lack thereof). I was afraid to feed him, for fear I'd cause more damage or stress, perhaps even causing him to shy away from the movement as the serpent star originally did. He seems to have plenty on the sandbed though, so I think if he were going to munch something, he'd go for that.

The other star seems fine, and is now happily taking krill from a pair of chopsticks.