What Is This Thing?

[wwinters]

Well I got some great rubble rock at Jeff's Exotic fish. Along with all the great mushrooms and polyps that came on the rock I also found these.

http://www.csulb.edu/~jwinter2/hitchhik ... hiker.html


The shrimp is about 1 inc from head to tail. I first assumed it was a mantis but the eyes don't look the same (not on stalks), the arms don't curl in when not in use and it is not particularly quick moving or stealth like other mantis I have dealt with. It spent most of the afternoon moving some sand in the front of my tank next to the glass. it also appeared to be eating little bits from the sand bed.
This guy is in a tank with mostly star polyps, a candy cane coral 1 emerald crab and 1 old hitchhiker crab. Should I remove him?

The "THING" was on a piece of the rubble I put in my house tank. I assumed it was a sponge. It started larger and more red/pink/orange. It has tentacles that sway in the currant, as well as sticky arm like things holding onto the rock and now glass. It is very slow moving, only a few inches in 2 weeks. but it is now attached to the glass and seems to be climbing up it. What is it?

I am sorry for asking an ID question on this board but no one has been able to help on the hitchhiker board.

 

[Entacmaea]

Hey there, hard to tell from the picture, but it looks like a pistol shrimp, especially due to its burrowing behavior.

As for the other thing, can't tell from the picture, could be some sort of bivalve, the "tentacles" are characteristic of scallops, like the flame scallop, but this is not a flame...

 

[wwinters]

If you click on the pictures you get a larger view. I haven't cleaned the front of ether tank in a while so I can't seem to get a good shot of them.

This must be the first shrimp I have ever received as a hitchhiker that was not a mantis!

"Thing" doesn't seem to have any shell, it is all a soft blob.

 

[jamesw]

The shrimp is certainly a snapping or "pistol" shrimp. Totally harmless and really quite cool.

The second URO (unidentified reef object) is probably a sponge or tunicate. It doesn't look like a file clam/flame scallop because it doesn't have a shell (so not a bivalve). The projections also come from all over its body.

HTH
James

 

[Entacmaea]

Hard to tell if it has a shell or not from the picture, but it is certainly not a sponge or tunicate, since it is moving...

If you look at the picture closely(now I know you can enlarge it!), it almost looks like it has two "stalks" or antennae, could be a kind of nudibranch or odd cuke... ?

Very cool though, whatever it is!

 

[THEFishHead]

It is a sponge- a Tethya sp. Please see Invertebrates: A Quick Reference Guide. This genus is one of a few genera that literally can walk across the substrate. They do so with those "tendril" like growths. They also reproduce asexually by forming daughter colonies at the tips of these tendrils.

Best Regards,

Julian Sprung

 

[Len]

wwinters,

Glad to see you got the help you were after (a response by Mr. Sprung, no less ) We've got no problems with you posting your question in here. The reason the Hitchhikers forum is in place is for archive and search purposes. People who are searching for previous ID questions have a far tougher time sifting through all the possible hits when doing a search in the General Reef Discussion (thousands of returns).

For this reason, Reefs.org encourages everyone to use the Hitchhikers forum when possible. Please take some time to browse the forum when you folks stop by to (if nothing else) see if you can help out a fellow reefer in an ID.

 

[Entacmaea]

A sponge that moves! Who knew?! Very cool. So now you know you have such a rare specimen, time to do some research to keep it alive!