What is this TEEEENY decapod claw.

[iamwhatiam52]

To get an idea of size, the reddish bump on the rock at the top center of the picture is barely 1 centimeter across. Note the mini brittle star arm in the upper right.

This second shot is the same picture zoomed in.

Thanks to Matt, kilroy217, for taking these super macro shots.
http://reefcentral.com/forums/showthread.php?t=1779876&page=2


These tiny claws shoot out from holes in the rock to feed. Squirting food near them brings them out. They are so small and translucent they are barely visible with the naked eye, and are lightning fast. They are so small and fast that for years I could not see what it was, even with a magnifying glass. I originally thought they were worms or tentacles, but later suspected they were articulated arms only because of how they moved.

For further information, the holes that the claws come out of are below the live coral portion of an old worm rock, but the coral and worms died. I bought it 3 years ago because it was home to two Paguritta crabs, one of which is still living today.

He is HUGE compared to the claw in the photo.

 

[LeslieH]

Interesting! I'd love to see the whole animal - no chance of an id beyond "crustacea" without it.

 

[iamwhatiam52]

I don't even think the whole animal could fit back out of the hole!

An exact genus and species ID is not expected.
Just a general idea: Shrimp? Crab? Squat lobster?

Maybe it's not even a decapod. I may need a review of my crustacean classification.

 

[Konolua]

I don't even think the whole animal could fit back out of the hole!

An exact genus and species ID is not expected.
Just a general idea: Shrimp? Crab? Squat lobster?

Maybe it's not even a decapod. I may need a review of my crustacean classification.

Looks lobster-ish. Some crabs have appendages (chelipeds) as such, but few in the "reef" section of the world. The long antenna also (for the most part) rules out a crab. Now, it could be a shrimp too, but most shrimp with long chelipeds tend to have them stick straight out, instead of more open. A classic example of the exception is the coral-banded shrimp that has a very open stance.

So, the "good" news is that it is most likely a fun creature to behold rather than any potential nuisance. I would say 80% lobster as a guess, 20% shrimp.

Keep the photos coming if you get any. This is a fun mystery!

 

[iamwhatiam52]

Looks lobster-ish. Some crabs have appendages (chelipeds) as such, but few in the "reef" section of the world. The long antenna also (for the most part) rules out a crab. Now, it could be a shrimp too, but most shrimp with long chelipeds tend to have them stick straight out, instead of more open. A classic example of the exception is the coral-banded shrimp that has a very open stance.

So, the "good" news is that it is most likely a fun creature to behold rather than any potential nuisance. I would say 80% lobster as a guess, 20% shrimp.

Keep the photos coming if you get any. This is a fun mystery!

May not be able to get more photos. Took 3 years to find someone who could get these because the thing is so tiny and moved so fast.

The long thing in the pic is not an antenna and not part of the same critter.

I am not the least bit worried that it is a nuisance.

Cool little things like this are one of the best things about salt eater tanks.

 

[LeslieH]

If you were to threaten me with red hot crab pinchers I'd guess some kind of galatheidae but otherwise I'll stick to crustacean. :-D

 

[romsoccer12]

http://www.youtube.com/watch?v=_0EuNhsz8CE
the claw looks like the same thing but larger
i dont think in the video its actually a pistol though

 

[iamwhatiam52]

http://www.youtube.com/watch?v=_0EuNhsz8CE
the claw looks like the same thing but larger
i dont think in the video its actually a pistol though

YUP!!!!!
Thanks romsoccer.
That is exactly how mine moves, and even the array of holes look the same.
Only difference is that the one in the video is bigger. I seriously doubt it is a pistol shrimp. The arms are long and claws are small, not thick like a the usual pistol shrimp.

I also wonder if it is one critter in a large cavity, or several in smaller holes.

 

[Sugar Magnolia]

That is amazing! The photos are so crisp!

 

[LeslieH]

Doh! Actually it could be a shrimp now that you all reminded me of this. There are many shrimp with long arms & even some alpheids that spend their lives in burrows, just reaching out for food. Here's one of these alpheids (with a nasty parasite attached) - http://www.flickr.com/photos/artour_a/3778193533/in/set-72157600178411914/ See how different the claw arms are compared to a "typical" alpheid? There are over 600 species in the family & most of them lack the big claws - which is why pistol shrimp is not really a good name for the whole family.

 

[iamwhatiam52]

Thanks Leslie.


artour_a's photostream has 7000+ amazing photos.
Most are of bugs, but there are also snakes, fish, crabs, slugs and yes Leslie, even woims!

Could well be some kind of shrimp, but I will never see the body because that would mean breaking the rock and likely killing it.

 

[ClamsOnDemand]

Yup that deffinatly is a shrimp claw. No doubt.

 

[LeslieH]

Thanks Leslie.
artour_a's photostream has 7000+ amazing photos.
Most are of bugs, but there are also snakes, fish, crabs, slugs and yes Leslie, even woims!

And if you look at the worms you'll notice who's being id'ing them :lol:
Art & I are good friends. We've even worked in the field together, two people united by our mutual love of photographing & collecting inverts.

Could well be some kind of shrimp, but I will never see the body because that would mean breaking the rock and likely killing it.

What a refreshing attitude! Most people just panic & immediately want to kill anything new. Of course Art & I would crack that rock in a second so we could cherish the critter in our own special way.....:hammer:

 

[iamwhatiam52]

What a refreshing attitude! Most people just panic & immediately want to kill anything new.

I have mentioned before that I am President of the Don't Kill the Hitchikers Club.

 

[ritter6788]

I have mentioned before that I am President of the Don't Kill the Hitchikers Club.

:beer: Can I be the Vice President?

 

[iamwhatiam52]

:beer: Can I be the Vice President?

Done!
Now we need a secretary a treasurer and some members.

 

[LeslieH]

Done!
Now we need a secretary a treasurer and some members.

Can mass murderers, er, ahem, marine biologists who love inverts join? :uzi:

 

[iamwhatiam52]

We will make an exception in your case, but no formaldehyde at club meetings.

 

[LeslieH]

Okay, but I'm not coming if I can't bring alcohol!

 

[iamwhatiam52]

Vodka dosing is permitted.