Help ID a clear (pest) polyp, please.

[Tang Salad]

This thing was stinging a colony of zoanthids. It was very hard to kill.

Sorry about the picture, but that's the best one out of about 50.:rolleye1:

http://reefcentral.com/gallery/data/500/136631hydroidmaybe_847.jpg

It's unique to me in that it doesn't have any tentacles. Instead, the head has a grouping of small ball shaped nubs. If you look very closely, you can see these little spheres.

Any idea what this was?

Thanks!

[Tang Salad]

To give an idea of scale, the three zoanthids you see are approx. 1cm across.

Each of the many spheres that make up the 'head' of the polyp were about 1mm across.

[Tang Salad]

Yes, it was very small. But it was also very deadly. It killed off about six zoanthids in one week.

[Tang Salad]

It also spend a second one, which was about 1/3 the size of this one.

[Tang Salad]

Ooops, that was supposed to say it "spawned" a second one...

[Tang Salad]

The picture shows the color quite accurately. It was mostly transparent, with a hint of blue; much like the color of a common jellyfish.

[Rendos]

Ever get the feeling you are talking to yourself?

[Gary Majchrzak]

It's when you answer yourself that you really need help! :)
Is it possible to get a better (clearer) picture of this thing?

[greenbean36191]

I don't think anyone is going to be able to get anywhere with a picture like this. There is essentially no detail visible.

[Tang Salad]

Thanks for the replies guys. Greenbean, happy to have your attention...

I apologize for the picture, and regret to inform you that I can't take a better one, because the polyp in question is now dead.

So, this is one of those cases where a thousand words will have to do what a good picture could have more easily done. Please bear with me and try your best to form a mental image.

(The good thing about this polyp is that its structure was extremely simplistic, thus a simple description can be very accurate.)

Structure:
The entire 'head' of the polyp was approx. 1.3cm in diameter.
The 'head' was comprised of 30-40 small 1mm spheres.
Each of these mini spheres was more or less the same size.
All of these spheres were arranged such that the entire polyp was also spherical.
It was a larger sphere composed of many smaller spheres.
(If you look at he lower-right side of the polyp in the picture, you can see the outline of the mini-spheres.)
There was no 'stalk' to be seen, although the entire head did sit slightly elevated off the rock.

Color:
It was primarily transparent, with a very, very light blue hue.

Activity:
It never moved from this spot, although it did spawn a smaller clone of itself. The clone eventually settled down a few inches away.
It had no tentacles extending out of it at any time.
It must have had nematocysts, because it stung and killed off a few zoanthids.

[reefD]

looks like a possible ball sponge and they can hurt other corals not by stinging but by smothering. does it change its shape size often? if not consider it to be a sponge. but not really sure as picture is blurred. just another possibility

[DSMpunk]

It might be a ball anemone. They are a type of mushroom that usually only open up at night. But the only type I have ever seen have orange "balls" for the tips, so maybe not.

[reefD]

i still think it could be a sponge

[Tang Salad]

<a href=showthread.php?s=&postid=8467983#post8467983 target=_blank>Originally posted</a> by reefD
i still think it could be a sponge

No, not a sponge. This was, as far as I could tell, a Cnidarian.

[Tang Salad]

<a href=showthread.php?s=&postid=8464128#post8464128 target=_blank>Originally posted</a> by DSMpunk
It might be a ball anemone. They are a type of mushroom that usually only open up at night. But the only type I have ever seen have orange "balls" for the tips, so maybe not.

It didn't change at all between night and day.
Thanks for trying!

[Tang Salad]

Bump.
Please and Thanks!

[Ryanqk]

looks like maybe it was a small bta?