Unknown hitchhiker

[davantalus]

Ladies and gentlemen of "Other Inverts",

I beseech you, please aid me in my quest to identify this evil scoundrel currently residing within the walls of my keep.

Any information leading to positive identification (dead or alive) of this "hitchhiking" menace shall be richly rewarded with praise and beer.

The beast in question! (http://www.youtube.com/watch?v=b_Afkfx-390) Look how he shrinks from the light!

Your faithful subject,
Dav

[Dratini]

It's not clear enough for me to make anything out but it moves quick. Maybe shrimp or crab?

[davantalus]

It seems to be rooted and filter feeding. My *guess* would be some sort of mollusk? It seems to have some sort of appendage that sticks slightly out of the cave to collect goodies. If you hit it with light or scare it, then it withdraws like you see in the video.

I guess my hope was that someone would be able to identify the movement more so than what's actually visible of it.

Do you suppose there's any danger in pulling out the rock and have a look for myself?

[Sugar Magnolia]

I'd pull the rock. I really can't make it out in the video.

[davantalus]

Well, 60 views on the video and nobody can tell... It's a keystone, but it's coming out the next time I feel like playing god.

[davantalus]

Well "ursula" has gotten slightly bigger and today we finally identified it as a barnacle... Well, I say that with 60% certainty. We saw a tonguelike food gathering apperatus and it does seem to have some sort of relocation ability.

Anyone ever had trouble with barnacles?

[mndfreeze]

I was unaware barnacles could move around at all other then their fan shaped filter parts. I thought they rooted in.

Could be another type of bivalve though. There are plenty that can move.

[kingfisher62]

I don't think it is a barnacle. Looks like the mantle of some sort of bivalve to me also.