starfish id please

I found this guy this morning cruising across some live rock. Not sure if he is friend or foe... guessing it is an asterina but it looks bigger than the ones I have seen before - about the size of a dime tip 2 tip.

 

asterina are usually lighter in color. Also its hard to get scale from the pic, how big is it?

 

He said its about the size of a dime. I have larger stars like that, I always assumed they were some sort of asterina, but they may be something different entirely.

 

Oh ya he did. I must have skipped that part. :-[ Its the right size for a asterina. Maybe just a dark colored one. All mine are cream to white colored.

 

Also you cant really tell from the pic - but the all of the arms are the same size

 

Welcome to 3Reef !!

Thats an asterina - they can be any color just that the tan/white ones are the most common. Considered safe if you will find the occasional person claiming that they eat sps - this isn't my experiance so I have no comment, but it were me I would let him be

 

They eat decaying corals from my experience. As soon as a zoa looks unhealthy or SPS polyps start dying, they are the first to hop on the coral to eat. Probably mis-associated with eating healthy corals. I have literally thousands of these and see them on my corals, but I can't say for certain they are doing the damage, or cleaning up what was already damaged. They love micro film and coralline, I know that. Just another creature adding diversity and helping clean up our reefs.

 

Looks very much like an asterina... I have thousands in my system, although like stated above mine are white (for the most part). When I first looked to ID these in my tank a member told me the white ones were good, and darker species should be watched closely. I can't confirm this is 100% true, but thought I would throw it out there. Mine have never caused me any problems, they crawl on my leathers while they are shedding to eat the skin, and climb the limbs of my gorgonians to help remove the algae.

 

If you flip him over, you'll see in is tan/being/white underneath. The colour on top is the colour he acquires from his environment.... like coralline.

This link has pics of mine... you can see they can vary even within the same tank.

http://www.lionfishlair.com/hitchhiker/asterina.shtml

 

Welcome to 3reef, looks like and asterinids star to me also.