Red Mithrax crabs
Hi,
I wanted to know a little bit more about red Mithrax crabs or some  times
called ruby crabs.  I cannot find any info about them.  << In my opinion they are just like green Mithrax crabs, only harder to find. >> I saw  someone on eBay
selling them for a good price.  They look exactly like the  emerald crabs but
red instead.  I have had emerald crabs in the past that  died.  Also, does
anyone know how big they can get? << I'll say about two inches across.  They eat algae, and lots of it. >> I have been told  that they eat algae is that
true? I really like the way they look and I think  they would be a great
addition to my tank. << They are awesome tank mates, but do eat algae... maybe too much algae. >>
Thanks,
Mo
<<  Blundell  >>

Swimming Crab Pics
Never found any ID on this little guy...he was SO cute.  He came in some
maiden's hair algae & was the exact same color as it.  I just bought some
more maiden's hair and have at 2 or 3 more in there...they're too shy to come
out yet, though.  He only came out when the algae went sexual and died off.
He wasn't afraid of anything in the tank, including me.  Got some short vid
of him swimming too...took some effort since he'd rather sit on my hand than
actually swim!
<Interesting... and can use video. Bob F>
Let me know if you want video too.

Looking for key to Persian Decapods
dear professor I'm study about fresh water crabs of Iran I need a key for
identification pls help me faculty of science Tehran university Iran
<Mmm, would have to research if there is such a reference in a college library. Not sure you're familiar with such bibliographic searches. Please see here re: http://www.wetwebmedia.com/litsrchart.htm 
Do you have access to BIOSIS on the internet? The Zoological Record? I would start with their databases. Bob Fenner>

Stocking/id questions
Hi WWM
<cheers>
question on stocking. I have a 50gal FOWLR, and a few polyps. presently I have 2 Percula clowns, a bicolor blenny, 2 peppermint shrimp, an emerald crab, various snails and hermits. I want to add 2 Firefish, a cleaner shrimp and a few more snails. do you see any problems with this? 
<seems reasonable... some chance with Firefish aggression to each other>
the Firefish will be mail ordered, should they be put into a quarantine tank, or just give them a fresh water dip to avoid the stress of moving from 1 tank to another? 
<all fish should be quarantined without exception and Firefish really should be purchased locally if possible. They are notorious bad shippers>
on another subject (thanks for your patience) I have finally
caught my hitchhiker crab. attached is a picture. any idea what it is? is it safe or should I remove it? also attached is a picture of hitchhiker snail. looks like a whelk to me, should it be removed?? the actual snail is a light green colour. Thanks Barry
<Barry and all WetWebMedia friends... please send any such pictures scaled down to a smaller 'Net sized image and never zipped (problems here). It absolutely crushes our mailbox with the amount of mail sent. Please resend my friend. Anthony>

Crab Hitchhiker
Crew:
I have discovered what appears to be a Mithraculus crab in the Indonesian LR in my refugium. Should I be concerned about negative effects? Because of the layout of my system, any attempt to remove it will almost certainly kill it. Thanks, Steve Allen.
<If it is truly a Mithrax crab no problem, esp. in a refugium.  Craig>

Re: unidentified crab sans QT 2/26/03
Thank you for your help...I know that quarantining for the rock is a necessary thing for the health of our tank...and we have been a bit lax in doing it lately (hanging head in shame.. G), as over a period of 2 years (and several QT periods) we have had no problems with live rock from this shop (our tank has thrived and grown tremendously)...however, that being said...that is no excuse for not being more careful...
<all correct my friend>
thank you for the reminder that just because we have not had problems so far...doesn't mean that we couldn't have problems in the future.    
<I must admit that I learned my QT lesson the hard way too <G>>
As far as the crab holding his claws in front of his face...we have seen no evidence of that.  
<perhaps not Calappa then... rather conspicuous>
He (or she) seems to keep them either tucked to the side or slightly out and down of the body.  I got a really great
look at it's back last night (o.k. it was a 2 AM peek at the tank.. G) and it's back was not as smooth as we had thought...it's very slightly bumpy...and it's body is  squarish in shape as well.  I will send in a pic when I can get one (looks like another 2 am tank peek...LOL) and send it to you.   
<indeed the best way for us to help ID for you>
We did notice one thing that may or may not help...around where it was at...was a bunch of what appeared to be algae in little balls around it.  Also...I might not have been to clear. but it's  back legs are hairy. but it's pinchers are smooth....if that makes a difference.  
<unfortunately not...  a couple hundred possibilities/species>
Thank you for answering my e-mail...and I must agree with what a lot of people have wrote about you guys. you are awesome!!!
<thanks kindly! It really is a labor of love>
Thanks again!  Will start re-searching the shame faced crab today.
Lee
<best regards, Anthony>

Crab Id please?
Hey Crew.. I think I've found the clicking source from my tank.
<nope... but I'm glad to hear your optimism :) You still will hear the clicking. Quite likely a small pistol shrimp from the live rock or sand>
Think this is it?
<Nope>
Some kind of crab?
<yep... this image shows a Mithraculus (AKA Mithrax or Emerald Green crab). They are good algae grazers but dubiously reef safe in the long run>
Thank you!
<best regards, Anthony>

Crab ID and trapping
I just got an id on a crab that hitchhiked on my LR from Tampa Bay SW, Gorilla Crab.  I can't find anything on this site, virtually nothing on the web.  
<that's because somebody made up that common name, bud... and there are no popular references to it commonly.>
Do any of you know the scientific name of this brute?  
<you'll need to send us a photo, my friend. Something more than a common name>
I know he's a bad guy and I want to get him out of my main tank,
<exactly>
but I'm having a hell of a time catching him. Thanks, Mike
<try leaning a small glass jar (like for pickles) in the aquarium against the rockwork with weighted meaty bait in the bottom. The crab will scurry down into the jar for the food at night but to be able to scurry back up the slick glass. Best regards, Anthony>

Crab ID
Hi guys,
I have an ID problem with a true crab. I’d love to send you a picture but I can’t. This guy is about 3/4" across the carapace, very hairy/bristly, coloration seems to be purple and white especially on his legs, banded in these colors. He is a hitchhiker on my FL Keys LR. I have several other crabs, all much smaller (half that size for the biggest) which appear to be of the "Sally Lightfoot" variety, although I’m not convinced that this ID is accurate either. Anyway, as for the big hairy guy, his claws are disproportionate with the left being dominant. His claws look just like the Stone Crab claws, which you may have eaten. (I may grow this crab to maturity just to harvest a claw. :) I plan to eventually have a couple of seahorses in this tank. Is he (he IS a he) safe for my horses (4"-5") or should I remove him to my refugium to fight it out with the Mantis Shrimp (also a hitchhiker) that lives there?
<I would remove.>
BTW, all have of my crabs have molted since I've had them, 2 months. I'm assuming that's a good thing.
<It means they are growing.>
Any idea on the ID?
<No, but better to be safe than sorry.>
Sorry, I know it’s vague. All these crabs seem to be algae eaters; but I know that all crabs are opportunists.
<Yes, very opportunistic and seahorses are slow and would be easy prey.>
Thanks, Mike
<You are welcome. -Steven Pro>

Crab identification
Greetings Bob,
A follow up to a previous email you answered regarding a stowaway on a piece of LR I recently purchased: here are 3 of the best pics I could get...he is a shy one. The next pic shows the yellow tips and "hairy" legs, claws are the same left and right neither is larger than the other). you can get a decent idea of them from the picture above.
a correction to my last email, the tank has been up for 2 months but the crab arrived with a 29lbs chunk of LR 2 weeks ago. As far as I can tell he only seems to be eating detritus from the sand, but I haven't been able to observe him with the lights off. Any help in identification would be greatly appreciated!
<the crab cannot be identified by species but the photo clearly depicts this specimens large crushing and hooked claws (in contrast to small pinching/algae cropping claws). As they say... "Form Follows Function". This crab is clearly an omnivore leaning toward predator with the hooked claws. It may behave for 10 days or 10 months... but rest assured that it will attack something desirable in time in the confines of an aquarium. Do remove (to sump, QT, refugium, or elsewhere)>
one more thing, in the first picture you can see a discoloration on the anal fin of the Flame Angel. It is actually a clear spot on the fin about 1.5mm in size...almost completely transparent. The Angel has been in the tank 2 weeks, with 2 weeks in a Q tank before that and seems very happy. Any clue to what this may be?
<no clue from the photo but does not yet sound pathogenic. Feed well and observe for changes>
Thank you very much, Emerson
<best regards, Anthony>