Macro or something else???

[Caracal]

Does anyone have an idea as to what this is?

I thought it may be macro algae, but there are animals inside. The outer "shell" (maroon in color) has a slit in it and the animal extends from that. They extend when it gets dark. They are beige in color and kind of look like a burr. Some sort of filter feeder?

[+o0zarkawater]

Animals inside?

Those look a lot like red bubble algae I used to have.

http://www.reefkeepi...ature/index.php

About halfway down that page.

Hopefully someone will have a better answer.

Edited March 21, 2010 by o0zarkawater

[Derek]

Looks like red grape calerpa to me.

[Caracal]

Yes, there are what appear to be animals inside. When I first got the live rock all I could see was the translucent "shell" and I thought it was algae or a tunicate. One night while the light was out I shined a flashlight in the tank to check something else out and I saw movement from these guys. I saw the "burr" retract into the "shell" when I shined the light on it. At first I only noticed the one. Recently I have noticed that there are more of them in their "shell".

[Bill B]

This animal inside scenario is very interesting. I would ALMOST bet money those are red bubble algae. I have had a small outbreak for some time now. I've seen them from a number of different angles and they all look like yours. The final proof, as pointed out to me, is if you pull one out a larger one, it will probably be oozing a clear slimy material. I wonder if it is possible there is some other 'thing' that somehow hides amongst it.

Bill

[caferacermike]

My guess is that they are red bubble algae with vermitid snails living amongst them.

[Caracal]

I saw something again last night, but I couldn't tell if it was coming from inside the red "shell". It retracted too fast when the light hit it. I suppose it could have come from a crevice or hole next to the "shell". The first time definitely looked like it came from inside the "shell". This morning I proded the "shells', but nothing moved. I pulled a bit of it off and it felt like leather.

[cmanning]

Does it come out when you feed your tank?....Watch carefully next time and see if it comes out during feeding time....maybe you'll get a better look at it. Also, at night,try to use a flashlight with red or blue filter...so you won't scare it.

-Cindy-

[Caracal]

I have only noticed them when the lights were out. I'll try filtering the light.

[+o0zarkawater]

What do the 'animals' look like?

I would think it might just be amphi/copepods living in the rock right there around the algae. They come out at night and run and hide back in the rock when you shine the light.

[Caracal]

That could be. When I first saw it I thought of a cockleburr. Fast mover when the light hit it.

[mooric]

Possibly a bristle worm in the rock behind the red bubble algae.

[Zarathustra2]

+1 on Red Bubble algae. Only thing that really feeds on it is emerald crabs.

http://reefcleaners.org/index.php?option=com_content&task=view&id=54&Itemid=81

Search for red bubble algae.

Emerald crabs: is there anything that they won't do.

I've had a few bouts of this stuff. Next time you do a water change you can attach a pick or a toothbrush at the end of your tube. Then you can scrape off the bubble algae and suck it out with the water at the same time. Makes it so you reduce the amount of spores in your tank.