Jellyfish?

[fishstick]

Some time ago there was a thread about a strange thing on the front glass of their aquarium. It was described as a central white dot with radiating spokes terminating in a white dot, the whole thing about 2mm across. I can't remember what the conclusion was but shortly afterwards I saw the same creatures in my tank, 2 or three of them. Today I saw a lot of white dots about 2 cms across sticking out of a crevice and waving about. I put a probe near and they withdrew quickly. I put a mysis shrimp near and it was grabbed by the 'thing' and taken into the crevice. I think this is a jellyfish of some kind and am concerned for my 2 small fish if it grows larger and can capture prey by stinging. Any ideas?

 

[chrissaysyes]

This could be so many different things...tiny sea stars, vermetids, aiptasia...

 

[1entra]

Any chance of getting a pic of it? It would help with I.D'ing it...

 

[Donya]

Jellies don't generally stick out of a crevice...there are a few speices of "walking" jellyfish that spend their time crawling on rocks, but I've never read of them doing what you describe. What you have sounds more like some sort of anemone or a corallimorph. White ball corallimorphs have sticky tentacles tipped with white balls and can easily acheive a tentacle span of 2cm, often much more than that. A pic would give a more concrete answer though, as 1entra said.

 

[Lynden]

Could be certain comb jellies, these are known to catch plankton by staying still and waving tentacles about.