Sunday, November 4, 2007

What are these things?

The live rock I bought supposedly came from Bali Indonesia. Several of the pieces of my live rock have some small brown polyps growing on them. Each polyp has eight tentacles that I can now see are somewhat feathery. If they are touched with the handle of my net, the tentacles retract into the stem. They seem to be spreading or perhaps more are just popping out of the rock the longer the tank is set up. Initially I was concerned that these were Aptasia anemones. However, they are too small to be aptasia and anemone tentacles aren't feathery.

Here are some pictures.

So what are these things and do I need to worry about them taking over the tank? I described these to someone at a LFS and he thought they might be Clove Polyps, a type coral. A goggle search found some pictures that look similar but not identical.

Can these be a type of stinging hydroid. Some pictures I found of hydroids also look similar.

Perhaps these are feather dusters. If anybody knows please comment.

I submitted a question to the Crew at Sara replied saying that they are probably some kind of clove coral and that they can be more invasive than aptasia or hydroids. She said I should destroy them before they get too comfy in my tank. Below is my email including her comments in [square brackets].

Clove polyps, hydroids or feather dusters- octacoral ID 11/03/07
Hello Crew,
[Good evening, Sara here.]
My tank has been running for three weeks with live rock that my LFS says came from Bali Indonesia. Several of the pieces have colonies of polyps growing on them and they seem to be spreading. I'm hoping you can tell me if these are something I need to worry about and ultimately remove.
At first I thought they might be Aptasia but I have ruled that out.
[Good thought, they're not aiptasia.]
I'm now thinking that these are either clove polyps or some sort of
[Well, the fact that they have eight tentacles per polyp is a big hint.
Thus, I would conclude that it is an octacoral of some sort.]
I guess it is possible they are feather dusters but I doubt that.
[Agreed. Not feather dusters...]
Each polyp is brown and has eight feathery tentacles. [good observation] The tentacles retract into the stem if they are touched with the handle of my net. The polyps are less than .25 inches in diameter. I'm not sure if these will actually sting me so I haven't touched them with my
Any help with ID'ing these and letting me know if and how these should be removed would be greatly appreciated.
[They're some kid of "clove coral." Unfortunately, some hitch-hiking clove corals can be as much a pain (if not more of a pain) than any hydroid or aiptasia. I've battled some that got into my aquarium for over a year now. I don't know if yours will be quite as invasive or relentless as mine have been, but if I were you, I wouldn't take any chances. Unless you really like them, I'd suggest you try to kill them off now before they get too settled in. Start with kalk. If that doesn't work, try vinegar. If that doesn't work... uh, there's always NaOH as a last resort (but that's very corrosive stuff, so try not to mess with it if you don't have to).]
[De nada,
Sara M.]