What is this?

[ryankamp]

I purchased this live rock (Alor rock) and just noticed this on the rock yesterday and managed to take a picture. It's pretty small, approx 1/4" at the most.

Any help identifying this would be awesome!

Thank you,

Ryan

 

[avshockey311]

Looks like hydroids to me.

 

[archie1709]

aiptasia

 

[CastleRock]

<a href=showthread.php?s=&postid=8330304#post8330304 target=_blank>Originally posted</a> by avshockey311
Looks like hydroids to me.

Dido hydroids

 

[pfish]

Looks like tube worms. Harmless

 

[ryankamp]

In doing a search on reefcentral I found this:

http://reefcentral.com/forums/showthread.php?s=&threadid=638479

Think I have the same thing? If so, then it's the polyp stage for a Crown Jellyfish.

Anyone have any experience with these and potential negatives/positives?

 

[avshockey311]

kalk paste them....coat them good

 

[dc]

Well I think they're hydroids also. There are always things that look similiar. FWIW I sent in some that look very much like those, and Dr. Ron id'd them as athecate hydroids.

 

[dippin61]

<a href=showthread.php?s=&postid=8330764#post8330764 target=_blank>Originally posted</a> by dc
Well I think they're hydroids also. There are always things that look similiar. FWIW I sent in some that look very much like those, and Dr. Ron id'd them as athecate hydroids.

the difference is the part of the mouth, that ron talked about. Commenting on the disctinctive "4 parts". in this quote

<a href=showthread.php?s=&postid=5549909#post5549909 target=_blank>Originally posted</a> by rshimek
Hi,

<b><font class="nf">THANKS!!!</b></font> for taking the effort to get the new images. It was worth it. They are not hydroids. The structure of the mouth region is pretty definitive. The four part or tetramerous symmetry of the mouth region visible in the first image is quite distinctive.

I believe your critters are the polyp form of a coronate scyphozoan jellyfish. They are possibly in the genus Stephanoscyphus or Nausithoe (there is some confusion in the literature about the proper name). These animals will bud off small "thimble" jellyfish. The polyps are reported to able to inflict a very nasty sting with their nematocysts, so be careful in handling them.

then there was this photo that showed the parts in question.

i too had thought mine were hydroids, i just went and looked, and i ahve these same things. the jelly's.