What is this??

Selter904 · Jan 31, 2013

So over the past week I have notices one of my SPS birds nest corals slowly dieing a branch at a time, today I found this little guy crawling around on one of the dead branches.

Could this be what has been killing it? Never seen anything like it before.

It appears to be some sort of star, and also seems to have taken on the colors of the SPS he was on. The picture quality is not all that great, it is about 1/4 the size of a dime.

Anyone know what this is?

ritter6788 · Jan 31, 2013

Asterina Starfish

Selter904 · Jan 31, 2013

I am assuming they are not a good thing? If i found one, is it safe to assume there are more in the tank?

Greg@LionfishLair · Jan 31, 2013

That's an Asterina star...generally, they're not a problem, altho they can multiply rapidly. It may simply be cleaning up the dead tissue on the skeleton, but there have been reports of them damaging corals. If you're not sure, remove it.

ritter6788 · Jan 31, 2013

If you have one you have 1000. Some debate on if they harm corals or not. Some even say there are a couple of different types, one coral safe and one not. I've never had any issue with them bothering corals and I have tons of them. They are algae grazers so a dead sps branch with a dusting of algae is a good feeding spot for them.

Selter904 · Jan 31, 2013

ritter6788 said:
If you have one you have 1000. Some debate on if they harm corals or not. Some even say there are a couple of different types, one coral safe and one not. I've never had any issue with them bothering corals and I have tons of them. They are algae grazers so a dead sps branch with a dusting of algae is a good feeding spot for them.

Thanks Ritter for the info. this clears things up for me, not to find out why my birds nest is dieing. Has been growing great for almost a year now.

Selter904 · Jan 31, 2013

Greg@LionfishLair said:
That's an Asterina star...generally, they're not a problem, altho they can multiply rapidly. It may simply be cleaning up the dead tissue on the skeleton, but there have been reports of them damaging corals. If you're not sure, remove it.

Thanks for the info!

Chameleon · Feb 1, 2013

Id your corals seem happy I would imagine he is good. Only time I have had problems with them is when I got rid of any algae for them to feed on by running a lot of GFO.

Pkunk35 · Feb 1, 2013

Please read over info in this thread which also has a link to Logzor's thread which is talking about the same topic.

I think some asterina are reef safe, but there seem to be a few out there that can munch on coral, from Logzor's thread I do believe i remember them being darker in color and splotchy, similar to the one you pictured.

https://www.reef2reef.com/forums/ge...91-extreme-slow-slow-tissue-necrosis-all.html