What is this?!

The somewhat blurry white thing on the side of the tank, it seems to have 3 appendages, white on one side, dark on the back, and the appendages are serrated. Is this a pest? I recently bought coral, and there seems to be another on one of the rocks the coral came on.

 

Is it an Asterina starfish? And if so, should I worry for my coral?

 

Yup. Asterina. I had some that never bothered my corals, but some people pull them out when they see them.

 

+1 To these guys. Some think them good, others think they munch on corals.

 

I like them. They are an interesting creature and are good for your reef. If you see them in your coral, then be careful, otherwise they typically stay away on your lr or substrate and glass. Good luck and long live the the stars!

 

I have one in my tank and it never ceases to illicit a squeal of delight from my wife. She loves the " baby" starfish. Never had a problem with it.

 

I think the problems come in when you have them in plague proportions. What I've read is that some varieties of them are harmless while some prefer to munch on coralline algae and hard coral skeletons. I do notice mine are usually on the corraline algae which worries me. I do pick some out of the tank if I see a bunch of them.

 

Mine is a true "hitchhiker"!

 

I have tons of the little guys in my tank. Never had a problem with them eating the corals. I've been letting them get a bit out of control so I have ample food supply for the harlequin shrimp I ultimatly want to add to the tank.