What is this on my live rock

There is such a thing but if I'm not mistaken, they all grow on a mat just like their green "relatives".

 

http://www.wetwebmedia.com/Cnidarians/Anthozoans/AnemonePIX/Aiptasia/Aiptasia.jpg

?

They look like glass anemones to me (but colored). The tips look very similar, however the body looks like a baby ^link.

 

I dont think its aiptasia. If you look really close (click on the picture to see it full size) you can see that the "tentacles" are somewhat feathery like a GSP. And yes there are brown star polyps but like the green ones the grow out of a mat. Although i do have some GSP that are growing but do not seem to be attached to the mat of the main colony, maybe the are brown star polyps that are just starting a colony and the mat will come in time.

Marc.

 

There are 100's of types of aiptasia. Here is the one in question....



marine menaces

 

as for brown star polyps, they look just like green star polyps, except tannish brown, lol.

 

SHAZAAM! Take a look at the 7th picture on this page under the title "Hitchhiker ID":

InvertIDFAQs

So, we know it's an anemone but Lord only knows what kind. Seems to be a stinger though!

 

amcarrig, if THAT'S aiptasia, then what the heck did i have?? it looked NOTHING like that... of course, it didn't look like the one that cav posted either... my "aiptasia" was brown with white rings on the tentacles, 2 rows of tentacles (one pointing up around the oral disc, and another pointing straight out) and the oral disc was a single color, and you could make out a "mouth".... and when i touched it with something, it would retract into the rock, and then i would see what i assumed to be stingers (long, very thin hairs)

 

That is not aiptasia. The description of your animal sounds like aiptasia.

 

I have a colony of clove polyps that look like that in the beginning of "new" growth. They have little green centers