Medusa worm (am I right on species ID)?

[Ooulophilia]

Hey, just thought I would share a picture of this wierdo - I have had him for a while. I think he is euapta godeffroyi. I had a pair of Periclimenes shrimp that would hang out with him, but both vanished one day.

 

[LeslieH]

Color looks wrong. Can you post a shot of the whole body?

 

[Freed]

Looks right to me. I had one a long time ago but it got sucked into the overflow and then into a pump.

 

[kmk2307]

I would like to see more pictures also. I was under the impression that these all had to live as symbionts of sponges or something. Is this a free-living one? Does it move around a lot? Where in the tank does it hang out?

 

[Ooulophilia]

I will take some "full worm" shots today - it is actually not too small - as for moving around, it does not have too far to go - it is in a small tank, but it is fairly mobile. It stays on the bottom mopping up the sand - it will respond to food being introduced - the mouth tentacles (I am sure there is a big word for that) extend and retract more frequently. I was unaware that they associated with other organisms, but I cannot say I know too much about them - it was sort of an impulse buy, I saw him when I had an oddball tank open, and it came in with the pair of shrimp, it was really cool when they were around, they were the exact color of the worm.

 

[Ooulophilia]

As requested, sorry about the wait:

This is after poking it - it does not like that

 

[Sk8r]

That's a medusa, I'm betting. I had one once, and it was in and out among the rocks, very neat creature.

 

[LeslieH]

A medusa worm, but not Euapta. The common species of Euapta look beaded due to the rows of large papillae going down their bodies. Externally this seems very similar to Opheodesoma australiensis - see http://www.meerwasser-lexikon.de/eng/77/2068/Opheodesoma/australiensis.htm
A specialist would have to check it out to be absolutely sure.

Medusa worms are members of family Synaptidae. A few of them seem to always living on sponges but not all. Most of them are detritus feeders picking up food from the bottom but a few seem to be filter feeders. Periclimenes imperator is a commensal on holothuroids and nudibranchs.

 

[Ooulophilia]

hmm - ticky snake sea cucumber - I like it! Every time I see a common name from Australia, it seems like someone has let their kid name the animal .