Hitchhiker IDs - Big Crab and Worm (pics)

[JoeMomma]

I just bought a whole pile of live rock from a tank break down and found the following along with it.

I was told that the crab is an emerald crab. Somehow I don't think it is.

I have no idea what the worm thingy is.

Should I add them to my display tank? The crab could go in my sump...

http://home.primus.ca/~vafahashemi/fish%20stuff/CIMG3507.JPG
http://home.primus.ca/~vafahashemi/fish%20stuff/CIMG3509.JPG

Thanks for any help!

[chatyak]

The crab certainly looks like an emerald crab, just minus the typical green color, and not sure about the bumps on the arm. Odd.

Not sure what the worm is. I can only think of flatworm, roundworm, peanut, and a couple others and it doesn't seem to fit the bill.

I'd try the crab in your sump.

[RRaider]

It's not an emerald crab. The black claws tell you it isn't reef/fish friendly so the sump is where it should go. I have no idea on the worm.

[rgrobe]

The crab's black pointed pinchers make it suspect. It seems the refugium would be the safest bet. The worm looks like a peanut worm. They are detritivores that tend to live in burrows and holes in the rock. They are relatively harmless. They don't do much and are seldom seen.

[divewsharks]

that does not look like an emerald crab from this angle. how big are the pinchers, are the legs hairy?

[Whys]

Not an Emerald. Possibly a type of gorilla crab, but unsure. That worm looks like the biggest flatworm I've ever seen. No idea what it really is.

If you wish to keep them, put them both somewhere you know you can get them back out, then just keep on eye on them.

Personally, I'd probably toss them both. Often when hobbyists don't recognize something, it's because it isn't reef-safe.

JM.02

[JCJHET]

The crab looks like a Xanthidae, not reef safe.
The worm could be Sipunculida (peanut), but not completely sure on that one.
Check this out http://www.chucksaddiction.com/hitchhikers.html

[Crustman]

Crab is xanthoid and other invert is a sipuncula. I agree with the above.

[JoeMomma]

Ok well last night I put the worm into the tank. He really did look like a peanut worm. He disappeared into the sand after about 30 seconds. Maybe my sandsifting star will eat him.

The crab was banished to the sump where he can eat pineapple sponges and battle it out with a large misbehaving emerald crab.

Thanks for the feedback!

[Whys]

What sized tank do you have?

Sand-sifting stars are notorious for depleting the benthic organisms in your sandbed, compromising the sandbed's role in the bio-cycle, and leading to the stars eventual starvation. Stars will eat their own legs when starving. If you see this, it is a sign of both its own ill health and your sandbed's.

Also, Emerald crabs don't typically misbehave unless very hungry. It would not be hard for a large Emerald in a small tank to run out of algae.

[JoeMomma]

I'm running a 120 with 60 gallon sump and 60 gallon refugium.

The star has been alive and moving around in the sand bed for over a year now. I can also see worm tracks along the glass so I know things are alive in there.

[Whys]

Good deal. You are one of the few to successfully keep a sandsifting star. Sounds like a nice system. Take more photos! :cool:

[Ncastro1981]

i have had a sandsifter star in a 46 gal for 2 years and moved both (2) to my 120 gal. never had any issues always look healthy

[Whys]

Ncastro, that surprises me. But this hobby is often full of surprises. Did you have any refugium as part of the 46g? I'm trying to determine where the threshold is on these guys as many of reported starvation is smaller systems. Could very well be an "established tank" issue. Not sure.

Thanks for the info.