Digitate Hydroids

[HappyHooligan]

I think I may have a cluster (5-6) growing on my newly added LR.
About an 1'' long. They appear similar to some photos of Dig. Hyd. Coloring alternates from brown to white with small white hairs and a small white bulb on the top.
They withdrew back into the rock immediately after I hassled them with a small metal rod.
They are out in full force today with the light on which seems to contraindicate what I've read about them being mostly nocturnal.
Also, my clown fish seems quite amused by them.

 

[thincat]

A picture would help. I don't think hydroids retract?

 

[HappyHooligan]

I'll keep trying for a pic. but we all know how that goes.

 

[Kurt_Nelson]

Agree that a picture would help. Digitate hydroids do retract. As you mention though, they normally are out when the tank is dark. They'll retract if they're hit with light suddenly, or are hassled.

I had (have?) one in my tank coming out of a cluster of Tubipora musica. Interesting thing to watch. It didn't seem to be the monster they're made out to be since it seemed to be living peacefully amongst the coral. I haven't seen it in a while though.

 

[HappyHooligan]

ok, got some pics...

 

[roka64]

That looks more like the arms of a bristle star.

 

[Zer0]

Yeah +1

I saw a picture that someone posted in their thread asking if this was a worm or something, and it turned out to be the arms of a bristle star. This looks exactly like that one did, so i agree with roka.

 

[HappyHooligan]

Do they ever crawl out or just hide and stick out their arms?

 

[roka64]

They move from time to time. Good freebie you got!

 

[Aquarium1]

What are hydroids?

 

[melosu58]

Xtalreef

You`ll see it here.

 

[Aquarium1]

Ok, thanks. Are the colonial Hydroids good or bad for a reef?

 

[thincat]

Here is a picture of one of my brittlestars. Excuse the picture noise, but this shot was taken at night without flash.

 

[HappyHooligan]

wow, very cool

 

[melosu58]

Ok, thanks. Are the colonial Hydroids good or bad for a reef?

According to that link it says "COLONIAL HYDROIDS
Hydroids come in many shapes and sizes. If you have something that sorta resembles a feather duster, but not really... look into hydroids. They can pack a mighty sting so it is good not to let them grow next to corals. They can be brown like these, white, pink, or other colors."

 

[Aquarium1]

So they're ok, just not good near coral?

 

[melosu58]

If it was me I would get rid of them. JMO

 

[Zer0]

Yeah, they may be ok away from coral, but colonial hydroids.. spread like colonies.. soo.. when they spread to your coral.. you wont be so happy.

 

[MichaelsLilGray]

does look like the arms of a bristle star.. ill 3rd that.