Crab Identification: Fiddler Crab – 10/15/09
Hi :)
<Ah, bonjour Marie, Lynn here today!>
I received yesterday 2 little red crabs from the Philippines and I'm not sure what they are because of the eyes. I think they may be fiddler crabs...
<You’re right. The overall shape/length of the stalked eyes and sharply pointed carapace seem to be fairly common within the semi-terrestrial fiddlers in the genus Uca, family Ocypodidae. The closest I can find is a photo of something alleged to be Uca arcuata (see this link: http://www.geocities.com/rainforest/canopy/5280/philip.htm ). Unfortunately, I can’t confirm the ID. Either the color/pattern varies quite a bit (as shown at the above link) or they’re different species entirely. Apparently, in the Philippines, these are mainly mangrove/shallow water/intertidal crabs that make their burrows in the mud and sand. Interestingly enough, I’ve seen a similar species being offered for sale on the internet, listed as a “Red Burrowing” crab in the genus Uca. >
..even if they don't have the oversize claw... maybe they're female.
<Yes, my thought as well.>
I sent you a picture, maybe you can help me with this identification.
<I sure wish I could give you a solid ID to species level, but there are just too many possibilities and not enough available information on the ‘net and within my research books.>
I don't want to give bad information to my customers.
<Good for you! I wish all merchants were this conscientious! Unfortunately, I have to add that these little crabs should not be kept in a fully submerged marine system. They’d do much better in an environment more closely resembling they’re natural habitat (mixed land/water). For more information on this group of crabs, please enter the terms (Uca or fiddler) into our Google search engine (http://www.wetwebmedia.com/Googlesearch.htm). I’ve seen several posts regarding solid red fiddler crabs with reports of them being very reclusive. Apparently, once added, they tend to burrow/hide and not come out much. In Barnes’ Invertebrate Zoology (sixth edition, pg. 717), it states that tropical species of this genus “tend to be active only during diurnal low tides”. That’s not a whole lot, even in the wild! Also, they’re still crabs and basically opportunistic, so hobbyists will need to keep these well fed to discourage picking/killing of desirable livestock.>
Thank you
<It was a pleasure, Marie.>
Marie
<Take care, LynnZ>

Re: Anemone & Crab ID Query  10/9/09
Hi Bob and Crew,
I saw this query come in but unfortunately can't ID the anemone in question. As for the crab, it looks like a Xanthid of some sort but unfortunately, there's just not enough information for me to take it any
further. I don't know the crab's size, where it originated, or if it was associated with anything else. In addition, I can't quite see enough of the carapace or claws. It looks like a lot of detail (how hairy...where hairy, surface texture/bumps) is lost/obscured because the crab's out of water, with water clinging. Anyway, all I can really offer is that it's likely a Xanthid. Sorry about that...wish I could be of more help!
Thanks!
-LynnZ
<Thank you Lynn... I can't tell much more myself. BobF>

Lynn/Crew,
I also didn't grab the query because of the crab ID, but I believe the anemone is a Long Tentacle/Corkscrew (Macrodactyla) Anemone. The picture quality is poor/dark so I'm not betting any money on it.
James
<Me neither. BobF>

Anemone & crab ID
Hi need an ID for this anemone. it's color is dark brown/maroon.
Thanks Siddharth
<Can't discern from this poor photograph. Bob Fenner>

Crab Identification 9/11/09
I have been unable to identify these crabs; and was hoping you may be able to help. They were collected in the northeast US in approximately 30 feet of water. The largest of the three is a little larger than an inch. A similar crab I was able to find on the internet was Cryptolithodes typicus.
<If it were Cryptolithodes typicus, they would be a long way from home.
Butterfly crabs are generally found in East Pacific waters.
I have no idea what type crabs these are. There are hundreds/thousands of species of crabs
<<... No... there are about 5k described species of "crabs" of which about 500 are "false crabs", Anomurans, like the Hermits... RMF>>
 and researching to accurately ID would be much too time consuming. As we are all volunteers with little time available,
our time is focused toward animals generally encountered in the tropical/sub-tropical
marine hobby. Now, if they were from tropical waters, an ID may be possible. Time spent Googling would be your best bet, is what we would need to do.>
Thank you for your time,
<You're welcome. James (Salty Dog)>
Cam
<<James, again, please don't respond to queries for which you don't have a qualified opinion. RMF who doesn't know what these are either. Am going to put in LynnZ's in-box>>

Re: Crab Identification
Good morning Bob,
Mmm, does the "hundreds/thousands" not fall into the "5k described species"?
<Mmm, perhaps I misread... as hundreds of thousands. Sorry re>
Not being a smarty pants here either, just thought I was in the ball park. You are correct Bob, I'm not qualified to ID crabs, especially species not related to the hobby. Was just trying to point out that we are not a research site as such, but a knowledge base for subjects associated with the tropical marine keeping hobby.
If I'm on the wrong track here, please do let me know.
Cheers,
James
<Thank you, BobF>

Help Identify a Crab: Possible Xanthid: Paractaea monodi - 8/22/09
Hello,
<Hello Susan, Lynn here today.>
Have you ever seen this crab before?
<Oh yes. I’ve seen this little crab before - or at least those like it. My best guess is that it’s most likely a Xanthid in the genus Paractaea, possibly a fairly cosmopolitan species: Paractaea monodi (Monod's round crab). Please see the following links for comparison:
http://www.meerwasser-lexikon.de/images/mP9JnaH6Rn.jpg
See several photos half-way down the following page and another good one at the bottom: http://www.ivanov.ch/redseaMax/crabes.html . By the way, there are also some “red-eyed reef crabs” in the genus Eriphia (family Menippidae) that look similar, but the carapace is not quite right (spiny/serrated edges instead of smooth, different overall shape and surface anatomy, etc.). See examples here: http://www.wildsingapore.com/wildfacts/crustacea/crab/eriphiidae/ferox.htm >
I have looked at many pages of crab pictures today and I cannot find one like it.
<Well, there are an awful lot of crab species out there!>
This crab was not purchased on purpose- it was apparently living in a piece of live rock that was added to the tank!
<Yep, that’s usually how they’re introduced!>
The shell is a very deep purple/black color under the lights and its eyes are dark orange/red.
<It’s actually a very attractive little crab, but an opportunistic omnivore and scavenger as well, with an unfortunate potential to destroy livestock.>
Any leads to identifying it would be appreciated.
<Hope the above information helps!>
Thanks,
<You’re very welcome.>
Susan
<Take care, LynnZ>
http://www.flickr.com/photos/infinitespirals/3844290588/sizes/l/
http://www.flickr.com/photos/infinitespirals/3843501515/sizes/l/

Hitchhiker Crab/ID 8/13/09
Can you tell me what type of crab this is and whether or not I should keep it in my reef tank? I have looked all over and can't identify it.
<I did a quick check with a 100 or so photos I have and cannot come up with an ID. Let see, that leaves about 749,900 crabs I have not saw:)
The crab does appear to be a specie of a swimming crab (last pair of legs appear to be swim paddles), and most are very predatorial. To be on the safe side, I would remove.>
Thanks
<You're welcome. James (Salty Dog)>

Crab ID – 7/24/09
Hello!
<Hello there!>
I am hoping you can assist with the identification of a crab I have had in my tank for approximately a year. It started out about ½" across but now has grown to well over 1". I have not seen him in over 6 months and then there he was tonight. I looked through all the available photos but did not see anything that I could be sure about. I can speculate that he came in on some rock from Florida.
<Unfortunately, I can’t see enough of the little fellow to be able to give you much in the way of an ID. All I can say is that it looks a bit like a Pilumnid (superfamily Xanthoidea, family Pilumnidae). Please see the following links for examples of crabs in this family for comparison: http://www.scielo.br/img/revistas/bn/v5n2/en_a03fig44.jpg
Pilumnus sayi: http://www.dnr.sc.gov/marine/sertc/images/photo%20gallery/Pilumnus%20sayi.jpg
Just bear in mind that all crabs are opportunistic omnivores that are usually okay when small, but can be a problem as their bodies and appetites grow. If (and that’s a really big if) what you have is indeed something in the genus Pilumnus, those usually stay fairly small. The same rules still apply though – if the crab gets hungry enough, it can cause problems.>
I am wondering if I should (attempt) to remove him from the tank.
<If the opportunity comes along (he’s out where you can net him) I’d remove him and find him another home. I wouldn’t go so far as tearing the tank apart to find him though. If you’re unable to get him out, I’d make sure he’s got enough food to discourage him from sampling something he shouldn’t and keep an eye on him (and your livestock). He may be getting a bit more bold because he’s hungry. You could try feeding him meaty bits of marine origin (shrimp/fish/clam etc), sinking pellets or the like. Obviously, if you’re noticing any damage to your livestock, I’d recommend getting him out of there sooner rather than later. You can always try to trap the little guy. There are some commercially available versions on the market or you could try the tipped jar method. Once you figure out where he hangs out within the rock, take a clean jar and lean/wedge it up against the area. Put a piece of stinky shrimp or bait in the bottom and wait. You might have to leave it in place overnight. The idea is that the crab smells the bait, falls into the jar and can’t climb back out. Sometimes this works, sometimes you end up with everything but the crab in there! Hopefully your little crab will be bold enough to come out in the open where you can net him without any fuss!>
I have noticed that starfish that I have added will get injuries that appear as if the insides are exploding out from them and I wonder if he might be causing them.
<Yikes. It could be but it could also be that the star is dying/reacting to adverse water conditions, rough treatment prior to (recent) purchase or any number of things. If it happens again, do write us with all pertinent info – water parameters, what species it is, what other livestock you have, how long you’ve had it, etc.>
Thank you!
<You’re very welcome! Take care, LynnZ>