Asterina Starfish Question

[Irishfist25]

I have a 180 gallon display with a 30g sump.  I have never seen asterina starfish in my display, but i recently bought a coral from a fellow reefer and there were about 6-7 of the little guys on the rock frag it came on.  I didnt want to put in my display right away, but decided to put them in my sump.  My thoughts are that they will eat any leftover food and stuff that would normally collect in my sump.  Is this accurate or do they only eat algae?  also, i realize there is a chance that they can still get into my display if they go through my return pump, are they really a pest?  i can take them out of the sump now and just avoid that possibility all together.

[AlanM]

I have not found them to be a pest  No idea what they eat.  If they eat algae, it's a very small amount of it.  Maybe they eat some kind of biofilm that you can't see?  They reproduce in my tank and don't bother anyone or anything.

[Jon Lazar]

I've personally seen them on my zoanthids.  When I pulled the asterina off, there was a wound on the zoa.  I can't be certain whether the asterina or something else made the wound.  But that was enough evidence for me to try to minimize asterinas in my tanks.  I also suspect there are multiple species that look similar, so behaviors could be different from tank to tank.

 

I avoid adding asterinas and pick them off the glass when I see them.  But I won't tear apart a tank to eradicate them.

[sen5241b]

I had them and I fanatically picked them out with a pair of tweezers until they were all gone. They tend to come out more at night. After a couple hours of darkness I would turn the lights on and pick a bunch out.

[rtelles]

I got them in my office tank from a frag I bought and they decimated my zoas. 

[Irishfist25]

Thank you everybody for your input

[Rob A]

I have had them eat zoas. They also seem to like coralline algae, but I can't say for sure that they eat it. They seemed to end up being like a plague for me. I had a 220gal set up and I would occasionally use  a small siphon hose routed down to a net over the sump and suck them out of the display. Even if they didn't eat the zoas there just ended up being so many on the glass that I didn't like the way it looked.

Edited December 12, 2016 by Rob A

[treesprite]

There are multiple species, some ok and some bad. Even if you only put them in your sump, if they multuply they will eventually end up in your DT.

[gws3]

Usually they are harmless when the have detritus available to eat.  I had an issue with overpopulation of them in my 300.  I even caught them eating the flesh off the edges of some encrusting montis.  I think they were starving, I had hundreds and not enoug.   I put a harlequin shrimp in the tank to take care of them.  Over the last 6 months he has survived on asterinas alone and has reduced their population by 90%.  I'm starting to worry they are not reproducing fast enough to keep up with his dietary needs, but I see him in the same spot every morning, and this morning he was eating one as usual.  I'm hoping the size of the tank allows the asterinas to reproduce fast enough on one end to provide him with a constant supply indefinitely on the other end where he has made his home.  So far so good at the 6 month mark.