Is this an Asterina? Is it dying?

[nyghtdancyr]

Saw this last night. It’s moving around on the rock but it looks awful like it’s falling apart. Couldn’t find a pic online of an asterina that looked remotely like this. Ideas?

 

[flsalty]

That's an asterina. It's probably splitting because that is how they reproduce.

 

[austibella]

Saw this last night. It’s moving around on the rock but it looks awful like it’s falling apart. Couldn’t find a pic online of an asterina that looked remotely like this. Ideas?

It will eat all your coraline algae . Bad stars.. they reproduce fast

 

[AcroNem]

They were Asterina, it has been changed but the hobby will still call them AsterinaThey aren't necessarily bad, there are a few species that can cause problems but are more rare to see in the hobby. Generally they are harmless.n

 

[Halal Hotdog]

Agree with @AcroNem , not all are bad. They are very hardy and not easily removed from a system. Typically if you see one then you probably have dozens to hundreds. They produce by splitting down the middle, and each half forms into a new star.

 

[SPR1968]

I would remove it immediately and yes it’s an asterina starfish.

Some types maybe ok, but many are not and they multiply at an incredible rate once they get established and many types will eat corals. I know I’ve had them big time in one of my tanks.

I certainly wouldn’t take the chance

 

[Wolf89]

Some types maybe ok, but many are not

You've got it backwards. ~95% of the types are beneficial and the test may eat coral. They are very uncommon

 

[SPR1968]

You've got it backwards. ~95% of the types are beneficial and the test may eat coral. They are very uncommon

Is there some research your aware of confirming this you could point me to as the quote of 95% being beneficial would be extremely useful to me and other reefers if it’s correct ?

This is not being challenging in anyway I just wondered?

 

[MabuyaQ]

Is there some research your aware of confirming this you could point me to as the quote of 95% being beneficial would be extremely useful to me and other reefers if it’s correct ?

This is not being challenging in anyway I just wondered?

Not trying to be a smart ... but where is your 'evidence' of the opposite as you were the one to make that claim first?

My opinion based on experience, Asterina make good members of your clean up crew. The population will grow fast and large initially but will also reduce once your aquarium gets established and more balanced. Nature will take care of them through competition and predation in a well run aquarium.
Yes there are starfish that look like Asterina (but may not be) that like eating zoas, but as long as it didn't come in on zoas it is very unlikely to be one of those 'Asterina'.