Help! Harlequin serpent star health

I have a 12-gallon nano with a harlequin serpent star that up to now has been very healthy and normal.

Recently, it has been spending more time out from under the rocks, and I noticed two wounds in its central body that look like someone took a bite out of it.

This is a highly mobile creature and sizable, and even my numerous hermits don't seem to stand a chance at hurting it. The only other thing I have noticed recently is an almost caterpillar-looking creature under my live rock.

The LFS stated I might be underfeeding this star, so I am starting target feeding. Could there be something feeding on it?

All help appreciated!!!!!!! Thanks so much!

 

How long have you had this guy and how big is he?

Serpent/brittle stars (I have both) are nocturnal, and can be seen squished up in a rock during the day, and crawling around out and about at night. Some, in the aquarium environment, will actually switch to coming out during the day time because that's when feeding time is. I know my brittle star will always stick some arms out during the day during feeding time to catch something, but my serpent star will sometimes come completely out of the rock work during feeding time. But they are still nocturnal...just "day" owls I guess.

You said you saw something that looked like a caterpillar in your rocks? Could you describe it further? It's most likely a type of worm, but there are several very common aquarium worms you'll encounter. Bristle worms, peanut worms, and other worms that most people aren't very fond of including flat worms.

 

Thanks for the reply. I have had him for about a month, and his diameter is about 5 inches, maybe 6. I did switch feeding to daytime.

Is it normal for an underfed star to "disintegrate"?

Two worms have appeared. Both look like a centipede with red legs, and those individual "plumes" down the spine. The one that was poking towards the star was minimum 3 inches long.

Also, are the salinity levels normal for a reef too high for a star?...1.25?

What parameters could be a problem? I normally keep temp at 83, no ammonia, no nitrites, minimum nitrates.

Thanks again!!!!!