 |
|
| Home | Marine Aquariums |
Freshwater Aquariums |
Planted Aquariums |
Brackish Systems |
Ponds,
lakes & fountains |
Turtles & Amphibians |
Aquatic Business |
Aquatic Science |
Ask the WWM Crew a Question |
| Please visit our Sponsors | ||||
|
Emerald Crab...black? 09/01/08 Hello WWM Crew! Just
curious what this crab is that I seem to have. He came along
unexpectedly with one of my corals that I purchased about 6 months ago.
He was quite tiny - about 1/2" or so - but just looked like a
little emerald crab - same shape, hairy legs...but seemed a little
darker in color. I didn't see him again in the tank and figured he
didn't make it...until about 3 or 4 weeks ago when
low-and-behold...there he was! MUUUUCH larger now...about the size of
an adult Emerald Crab....only pitch-black in color. Green Emerald Crabs
are quite common in every fish store I've ever been in, but
I've never seen a variety that is black. Any idea what I have? Just
an odd-ball colored variety of the Emerald Crab? <It is likely some
species/variety of Mithrax crab. Sorry, but without a pic I honestly
can't tell you much more than that... :-/ > I'd send a
picture, but the only times I've seen him he's hiding between
the rocks. Thanks, Chris <Do keep an eye on him... Best,
Mystery Crab - 08/11/2005 Hi <Hello.> Today I Purchased some live rock and in it came out a really sweet little bright red crab around 1inch across and scarlet red in colour have you any ideas what it could be. It buried itself in the sand substrate. The rock is Fiji rock. <Many, many possibilities.... See here for starters: http://www.wetwebmedia.com/marine/inverts/arthropoda/crabs/swcrabs.htm . > Regards, Charlotte, In the UK <Wising you well, -Sabrina, in sunny silicon valley, CA, USofA.> Red crab.... possibly from Fiji.... ? 8/13/05 Hey there, Bobster.... Quick question. The gal with a (very) undetailed crab ID request yesterday has replied, and given a (slightly) more detailed description.... Wonder if you can point me in the right direction.... <Saw this... and with the provided info... don't know...> She say it has roughly the shape of Cancer antennarius . It has elongated black eyestalks and black "joints". It is currently about an inch across. The crab has burrowed into the substrate, and come back out again. It came in on Fiji live rock that she recently added, but I am not at all convinced that that means the crab originated with the rock from Fiji. Don't know. <Me neither> Anyhu, the elongated eyestalks thing and small size, as well as burrowing, makes me think Uca/fiddler-type crab.... a couple red ones I know of/have seen.... but I really don't know. Any thoughts? -Sabrina <Really am at a loss... not an unusual state here... I say (re such crab unknowns), "When in doubt, take it out" or at least keep a keen eye on it for opportunistic predation. Cheers, BobF> Mystery Crab - III - 08/12/2005 Dear Sabrina, <Hi, Charlotte!> The crab I have looks very much like Cancer antennarius although it is very small and scarlet red not brown. I present it is about 1inch across. The crab has finally come out of the sand substrate. It is still bright red with a smooth shell, the eyes are on long black stalks also it has black joints. Hope this is still some help because there was nothing like it on the list you sent other than the one I labeled. Regards Charlotte Windsor <This description is of some small help, but unfortunately, just not enough for an accurate ID.... You might google for images of genus "Uca", but I do not know if that will be fruitful at all. I asked Bob his ideas, as well; he, too, is at a loss. He suggests " 'When in doubt, take it out' or at least keep a keen eye on it for opportunistic predation." So do be wary of it - were it me, I would probably set up another small tank for the guy, should he prove to be a problem. Wishing you well, -Sabrina> Mystery Crab - IV - 08/12/2005 Hi Sabrina <Hello, Charlotte.> Would a photo of the little guy help ? <Mm, not terribly likely, but it sure wouldn't hurt! We may *possibly* be able to nail it down a little.... Worth a shot.> Charlotte <Wishing you well, -Sabrina> Crab ID 7/28/05 WWM Crew <Mike G> I have spent hours looking for what the ID of the crab <Good luck. Crab identification is very difficult, indeed.> I have in the attached photo is, and anything that I could find out about it. <I'm sorry, we didn't receive a photo.> I have a 125 gal, some coral reef with 100 lbs of live rock and a few fish, he appears he could be a mean little fellow, and I do not have any idea how big he will get. <In general, I don't trust crabs. Guilty until proven innocent is what I think of em. I'd isolate him until you can prove him either innocent or guilty.> Thanks for your help in advance <Welcome.> Mike Re: Crab ID 7/28/05 Sorry I did not attach the first time, thanks for your timely first response, maybe you can give me more info with this, thanks again, Mike <Still did not receive it. Mike G> Hitchhiker Crab; I am not sure which it is; hair algae and do you know Kenny Doubt, aka 'Sharkbite'? 7/17/05 Hello Bob. <James> I made a discovery as I brought my live rock home from my favorite LFS the other day. I now have another crab. I was fortunate not to have put my fingers into the hole he was hiding in and noticed it while I was examining the rock. It is somewhat large and I estimate nearly an inch and a across the carapace. It is black or a very dark green and the joints appear white. I am not certain, nor is the owner of LFS, if it came from his tank or not. This is because we got rock from both the holding/curing area and then some from a main tank. This specimen neither seems to bother the skunk cleaner shrimp, which I transferred in from the 5 gallon, nor the red scooter blennies. How do I go about looking up what this crab is? <Mmm, a pic... the Net... sending out to forums that deal with such> I do not see it much but I know where his hiding spot is. It seems to be content to pick at the rock and only raises its claws when anything gets into its comfort zone; standing ground but does not appear overtly aggressive. I am going to try and catch it and bring it to the LFS to see if he can identify it. If it was in his tank I will probably keep it and pay him something extra as it has lived peacefully in that tank for years and did not bother the fish that are in it. If it is not his then it is a mystery and came from the tank he broke down from a customer and I think not worth the risk. I also made a discovery in that the branched coral (somewhat obviously now is coral) looking rock had corals coming out the tips. They are red and dark purple, bubble-like in appearance. This is going to be somewhat more of an issue as unless I can get a decent picture I know if I remove it from the tank and take it the store odds are good it will be a day or so before they will open back out. Besides, I do not wish to stress them. I do want to take care of them properly and I feel that is easiest a task if I know just what they are. I was speaking with JJ Perez the other day at his store in Ridgefield Park, NJ. We thinks the problem (algal growth) I have is with phosphates and hard Garfield water. He mentioned the hardness of the water (he measured at about 550ppm KH a while back) <Yikes, liquid rock!> was great for breeding African Cichlids. I have limited the lighting time periods and tried reducing feeding. I have been diligent in trying to pick as much of this hairy nuisance as I can off the rock but unless I get it out it just sticks elsewhere. We (my wife and I) have decided on getting a small RO unit but have not yet. The Mithrax crab is not doing his job in the 5 gallon tank as the Royal Gramma pursues him mercilessly once he is seen out of his hiding spots deep in the rock. The cleaner shrimp was removed as the fish was constantly picking at him though I would have preferred to wait to add him into the 55gallon tank. It is nice to see him no longer forced to hide in the top corner near the heater all the time and this does make cleaning the smaller tank easier. I think I asked about Kenny in an earlier email (now like all things on my old drive) lost. JJ mentioned that he was a fish collector and worked at a distributor in Hawaii. I just thought he was a cool surfer originally from New Jersey. Small world indeed! <Don't know him as far as I'm aware... do think I've been to the NJ store with my bro-in-law Pat though. Bob Fenner> Present (mostly constant) tank parameters: pH: 8.2-8.4 SG: 1.0228 (55 gallon) 1.0224 (5 gallon) KH: upwards of 300ppm (see JJ's measurement above) NO2-: 0ppm NO3+: 15-20ppm (55 gallon) 20 ppm (5 gallon) Temp: 78-79F average. Gear on the 55 Gallon: 260 Watt Coralife power compact, Aquaclear 1100 filter and a Penguin 1140 Power Head (directing flow diagonally towards the front of the tank) mounted on the left end from the filter which is on the right/middle side. Prizm protein skimmer not hooked up yet (I am thinking of placing it next to the filter if it will fit) as per recommendation (wait three weeks) from using stress coat to treat the tap water for metals and Cl ions. Oh, yes I am running everything off a GFCI… Stanley makes a good one available at Home Depot and it has 8 plug inputs for about $27. I am also going to get a UPS… because you never know when you may not have power… Any suggestions on things I should change or add? Thank you for making such a great website and providing so much great information in your book (wife calls it my 'fish bible', lol) Bob. James Zimmer Unidentified crab type creature Hello All, I just bought a yellow and purple double sea-squirt from live Aquaria.com (Polycarpa aurata). It came with some interesting hitchhikers on the small rock it is attached to. What seems to be a Christmas tree worm or some such double barreled triple banded fan worm. However, what I am interested in ID'ing is some sort of crab I think. Unfortunately it is much too small for me to get a picture of (I need a telephoto lens). There are at least 5 in close proximity. They live in very well defined holes. All that sticks out is a pair of eye stalks, somewhat like a hermit crab, two long antennae, and some funny pincers. One is predominately larger than the other, but both are very flattish with a purplish color and small white spots that blend into coralline algae as great camouflage. The pincers are very flat and kind of wide and bladelike like a canoe paddle blade. They have a funny behavior of resting their pincers hanging out the edge of the hole like they are relaxing on their balcony or something. All of them do this. Again, all I can see are the eyes, antennae and pincers. The whole critter is very small. Because of the shape of the whole its body must be more tube like than a typical round crab shape. The pincer length of the largest one is only about 2 mm. The antenna are maybe 4 mm's in length. I don't know how long the whole crabs are because they won't come out of their hole. Anyway...any help would be appreciated...Collin >>>Greetings Collin, Even if I were the worlds foremost crab expert, I could hardly hope to identify the species you have in your possession with such a description. There are THOUSANDS of species, positive identification is often difficult even with the best of photos. In all likelihood they are harmless, very rarely have I had problems with crabs unless they were fairly large. Cheers Jim<<< Caribbean Crab ID Greetings, I am seeking assistance in identifying a crab that surfed his way in on a piece of Caribbean live rock. We have seen glimpses of him here and there, but never enough to know whether we had a Mantis Shrimp or something else. We were finally able to get him out of his hole, and were surprised to see a crab. If he is non-threatening, I will return him to the rock. Currently, we only have Astraea snails, Nassarius snails, Blue-leg Hermits, and a pair of Yellow-Tail Damsels. Thank you in advance, Brian Domke >>Hi Brian. I don't actually know what it is, but a good rule of thumb is not to put it back in the tank. Most crustaceans are opportunistic carnivores and probably will, at some point, eat something you want. Rich>> Filter feeding crab hey guys the other day I was strolling thru the LFS and noticed this crab that had arms that were modified for filter feeding (really cool) I couldn't keep my eyes off it. of course the employees didn't know what it was, any ideas? << An anemone crab, maybe a Neopetrolisthes maculata. >> thanks, Ryan << Blundell >>
Crab Identification 19 Aug 2004 <Hi Brian nice
to meet you, MacL here with you this afternoon.> I purchased two
small crabs from LFS. They are bright red with blue eyes that are
extended away from the body. They have tiny claws that are even in
size. No banding or striping on the body, just solid red. As soon as
they hit my substrate they burrowed into the live sand and have only
been seen once since (about a week ago). LFS sold them as fiddler
crabs. <Fiddlers males generally have one claw that's larger I
believe. But you could have two females.> Have no reason
to doubt that, but can't seem to find any information on line the
identifies them as such, nor fiddler crabs that are exclusive to life
in the water, not on land. <Have you been through this http://www.wetwebmedia.com/marine/inverts/arthropoda/crabs/swcrabs.htm
to see if anything looks similar? My first thought was a pink Mithrax
crab (least that's what they are sold as around here)> Thoughts?
Identification? Resources? <Take a look at the threads off that site
and see if you can identify it. Good luck, MacL>
Thanks!
Unidentified crab <Hi Cyndi, Mac here> Please help!! We have found a tiny crab living in our live rock. <Not always a good thing, some crabs can cause some troubles.> He is about a 1/2 an inch wide from left leg to right leg and they are hairy looking. <Cyndi, could that be feathery and not hairy?> He is white and appears to have small purple spots on each joint. He has more purple stripe like markings on his back and his eyes appear to be purple. He moves kind of slow and generally stays in a little alcove on top of a large rock. <Just from your description, its possible he might be a type of porcelain crab similar to Neopetrolisthes maculata or possibly of the Lissocarcinus family> I can't find a picture of one like him anywhere on the net. <There are many wonderful sites that have some pictures of crabs.> I may be able to get a picture of him out of our aquarium if you can't tell from the description. <A picture would be IMMENSELY helpful.> Thanks in advance for you help. C.S.
Mystery Crab - 03/15/2004 Hi, we love the site, it has been very helpful. <Glad to hear it. Sabrina here, at your service.> We have a 55 gallon tank with a yellow tang and some damsels in it. We recently added some shrimp "coral banded and a peppermint" they get along well. We also got a rather red crab. It said on the tank it was a fiddler crab, but we are not sure. <Did the fish store have the Latin name for the crab, perchance?> We can't find anything that looks like it on your site. <There certainly are lots and lots and LOTS of crab species in the world.> He/she is very red/orange and is the size of a quarter and we never see it. He or she hides under the live rock. <You might be able to get it trained to come out for food, if you target-feed with a turkey baster. It would take a while, but crabs can become very, very outgoing.> We just don't know what it is for sure. <Neither do I, without a picture, I'm afraid.> Are our fish in danger? <Tough to tell, without ID'ing it. However, at such a small size, and with active, fast moving fish, I don't think there's a whole lot to worry about. The shrimp would be at more risk than the fish, and even still, they'll likely be fine.> We're very new at this, need some advise - he/ she doesn't look like your pics. <Speaking of pics, if you can snap a digital photo of him and email it to us, somebody may be able to give a positive ID. Wishing you well, -Sabrina> White crab inside scallop 2/14/04 Recently I've noticed that the orange on this inside of my electric flame scallop was deteriorating. <regardless, this is a very poor specimen for captivity... most slowly die within one year of purchase. Please do resist buying another> I thought that it was either normal or maybe the scallop was dying. Well today my scallop turned around so now I can see the complete inside. But I found a crab inside! Can you identify this crab and tell me some more about it? <not really without a picture or detailed scientific description. Else you are asking us to name a faceless creature <G>. Kinda tough> I think my scallop may be doomed, but this is a cool looking crab. <the carb may be commensal, obligate (if so he will die soon too) or simply a hitchhiker. Hard to say. Agreed though... fascinating> Thanks so much and I love your site! -John <best regards, Anthony>
Crabs inside of live oysters I recently bought some live oysters from the supermarket and while shucking them I found small crab inside that was still alive. I was wandering what kind of crab this would be. the oysters were farmed raised in Weens Va. can I put this little crab in my fish tank ? <Might be the commensal Polyonyx gibbesi> will it adapt to fresh water? <Not likely> if it survived all of this I don't see why I cant keep it alive until spring when I can take it back to the bay. I accidentally brought home a fiddler crab from the Florida keys in a plant and kept her for two and a half years until I returned back to sunshine key to release her ! <Neat!> what a wonderful experience. she was the size of my pinky fingernail and when I released her , her body was the size of a quarter. she had shed her shell several times in a shallow bowl of water. even during the full moons. I kept all of her shells. please let me know how I can collect information on this subject. sincerely, Margie Petro <Do try "plugging in" the above scientific name in your search engines and seeing if this is the animal. Bob Fenner>
Crabby Hello again, <Hi Steve, Adam here at your service.> I have recently discovered a small crab that either came attached to some indo-pacific live rock or Fiji. I am coming to realize that this is not overly uncommon. <Very common actually. In fact, my tanks have been set up for years and I just discovered a new crab a couple of weeks ago. They can also hitchhike on corals.> I have no picture for you, but I can tell you his body is purple, his claws are as well, but the claws have white tips on them. his legs are zebra like (black, and whitish yellow stripes). his complete body (including legs) is probably a little smaller than a penny or dime. <Providing any reliable ID from your description is impossible. And as you read on, the ID really doesn't matter IMO.> I understand that most, if not all are dangerous tank species. I was just wondering how dangerous this guy would be to my corals such as: xenia, button and star polyps, mushrooms, and tree corals. <You are absolutely right. Many aquarists have learned the hard way not to trust any crabs (even the supposedly "reef safe" hermits, emeralds, etc.). This crab could be around for a while without causing noticeable damage... until it is the size of a quarter or half dollar. Also, most crabs aren't neat and considerate. If they are hungry, they don't pick an apple from the tree and eat it (so to speak of course), they knock down the tree, break all the branches, take bites out of a few apples and then smash the rest.> I would like to keep him as long as possible, as I really like him. Any and all information that you could supply me with will be greatly appreciated. <Can you tell that I am not a crab fan? If you choose to leave it, watch it carefully and try to target feed it. If it isn't hungry it will be less likely to be destructive. When you do decide to remove it, a baited beer glass placed upright with the rim against a rock near where the crab hangs out makes a very effective trap.> Thank you for the great web-site etc. and I'm sure I will talk/write to you again. Again thanks for all the help. <Thanks for stopping by! I will look forward to chatting again. Adam> Steve
|
|
|
Features: |
|
| Featured Sponsors: |
