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FAQs about Marine Crab Identification 11

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Related FAQs: SW Crab Identification 1, SW Crab ID 2, SW Crab ID 3, SW Crab ID 4, SW Crab ID 6, Marine Crab ID 7, Marine Crab ID 8, Marine Crab ID 9Marine Crab ID 10, Marine Crab ID 12, SW Crab ID 13, SW Crab ID 15, SW Crab ID 16, SW Crab ID 17, SW Crab ID 18, SW Crab ID 19, SW Crab ID 20, SW Crab ID 21, SW Crab ID 22, & Marine Invertebrate identificationMarine Crabs 1, Marine Crabs 2Marine Crabs 3, Marine Crabs 4, & Crab Behavior, Marine Crab Selection, Marine Crab Compatibility, Marine Crab Systems, Marine Crab Feeding, Marine Crab Reproduction, Marine Crab Disease, Micro-Crustaceans, Amphipods, Copepods, Mysids, Hermit Crabs, Shrimps, Cleaner Shrimps, Banded Coral Shrimp, Mantis Shrimp, Anemone Eating Shrimp Crustacean Identification, Crustacean Selection, Crustacean Behavior, Crustacean Compatibility, Crustacean Systems, Crustacean Feeding, Crustacean Disease, Crustacean Reproduction,

Crab ID: Possible Liomera sp. -- 9/29/08
Hey folks,
<Hi there, Joe.>
Maybe you can help me ID this hitchhiker I got on a recent order of coral from Tonga.
<It's a pretty little thing, isn't it?>
It is nocturnal and is currently about 3/8 inch in size (about like a popcorn kernel). This is the best photo I can get for now but its strange pink color should narrow the list.
<Let's hope so! It looks like something in the genus Liomera, possibly Liomera rubra: http://www.botany.hawaii.edu/basch/uhnpscesu/htms/kalainvr/images/crustacean/Lio-rugataK26x7.jpg
or Liomera margaritata: http://www.conchology.be/es/availableshells/shellsforsaledetails.php?uniquenumber=425625#f  >
Joe Faszl
<You're very welcome. Take care --Lynn>

Re: Crab ID: Possible Liomera sp. -- 10/2/08
<Hi there, Joe!>
That looks like it.
If it can find a food source I hope to keep it around for a while.
<Sounds good. Crabs tend to be omnivorous/opportunistic creatures, so chances are it'll be fine for quite a while. You can also offer it meaty bits (of marine origin) and/or some sinking food pellets. Keeping the growing crab well fed will help discourage it from sampling some of its fellow tank-mates!>
If it gets too big, there is always hot garlic butter ;o)
Thanks for the information and the quick reply.
<You're very welcome, Joe.>
<Take care, -Lynn>

Reef Aquarium Hitchhiker Crab ID Needed? 9/26/08
Hello, I wondered if you could identify this crab?
Thank you in advance~
<Mmm, I can't seem to find in my ref.s... Can you wait a till 10/6 or so? Will ask LynnZ to look at. BobF>

Re: Reef Aquarium Hitchhiker Crab ID Needed? 9/26/08
Alright, thank you for the help.
It has stumped me, he almost has the body of an Arrow Crab, legs of a Hawaiian Swimming Crab of a Sally Lightfoot.
Then the claws are really interesting, it looks like one's for veggies and one's for meat?? lol.
<An apt description! Let's see what Lynn says. Cheers, BobF>
Mystery crab 08/08/2008 good day from Oregon <<Good day from sunny England. Andrew here today>> I am new to reefs (saltwater for the truth) and have found out that you inherit what is in the live rock . I have found around 5 brittle star type fish 3 or 4 other types of star fish , red feather dusters along with other brilliant thing AND one not so good guy . on the picture attached ,the best one I could get of him , he is in the center of the photo in the hole . has pinkish white hairy legs dark black main body . Good guy bad guy? anyways I found the mention of traps, I am going to try to capture it tonight . if you could ID it . Where I got the live rocks, they says it a hairy crab (little vague if you ask me). <<A little too hard to say / make out from the picture you supplied. Please do look have a look here, http://www.wetwebmedia.com/marine/inverts/arthropoda/crabs/swcrabs.htm and related FAQ's and articles. Maybe trap the crab, put in a plastic tub and photograph / re-submit and we shall try again.>> James <<Thanks for the question. A Nixon>>

Hitchhiker crab 07/28/2008 Hi <<Good evening, Andrew today>> Caught this crab this morning. I knew he was in some Live Rock last October. Amazing markings. Do you have any idea what species he may be? <<My educated guess would be that its a Anomuran crab, from the family Porcellanidae family. One I would consider reef safe>> Cheers, Michael <<Thanks for the question, A Nixon>>

Hitchhiker Crab -- 7/28/08 Hi, guys! <Hi there!> I will keep it short. I found this dude in my live rock and flushed him out by removing the rock and running fresh water through my star polyps where he was living. <Yikes!> Do you know what species he is? <I wish. Unfortunately, I can't see enough detail to even narrow it to family/genus level. Suffice it to say though, that crabs are predominantly opportunistic omnivores, so the potential is there for it to pose a threat to other livestock. This is particularly true as the crab grows in size. If the crab is fairly small right now, you could either leave it in place, monitor and trap if/when necessary, or simply find it another home elsewhere. It's up to you.> I searched your site and the internet and found many nice crab photos but none like him. Thanks. <You're very welcome!> http://www.fishpondinfo.com/photos/crustaceans/crabs/scary1.jpg  http://www.fishpondinfo.com/photos/crustaceans/crabs/scary2.jpg  http://www.fishpondinfo.com/photos/crustaceans/crabs/scary3.jpg  http://www.fishpondinfo.com/photos/crustaceans/crabs/scary4.jpg  It's ok if you don't know. <Thanks, it always frustrates me to not be able to get an ID for someone, but crabs are notoriously difficult in that regard. There are just so many thousands of possibilities that it boggles the mind. Our best chance at identifying these neat little creatures begins with detailed/high resolution photos from above and below (including all legs), as well as views from the front, showing the claws, eyes/eye placement, etc, along with information such as size and where it came from. Even then, it can be frustratingly difficult due to the lack of readily available photos of every crab on the planet. With that being said however, we can usually narrow things down to family level which is at least a good start! Again, I apologize for not being able to supply this for you. Good luck with your little crab. :-) Take care, -Lynn>

Re: Hitchhiker Crab, Plus Possible Poriferan -- 7/28/08 <Hello again!> Thanks so much Lynn even though you didn't know what he was! <You're very welcome!> I thought I was the only person on the internet who still answers all questions and promptly! It's hard work! <Well, we do our best, and yes, it can indeed be hard work -- but it's well worth it!> I run a huge web site myself mostly on freshwater aquariums and ponds. <Excellent, so you can definitely relate, huh!> People don't realize how much time it eats up to respond to so many questions. I thought my photos were pretty good, in fact better than looking at him in person since he's so tiny! <I'm sorry, they were indeed good photos, especially for a small crab! It's just that when it comes to identifying these critters, and especially crabs, it's all in the details. These include shape/texture/color of the overall carapace, whether it's smooth or 'hairy', the number of spines/shape of the carapace edge, eye placement/color, length of eye-stalks, how many legs, the shape/length/color of legs and claws and whether there are any 'teeth', spines, bumps, etc, on them, the shape of the tips of the claws (are they pointed, blunt, or spatulate), the depth of the body, etc, etc, and that's just the basics. LOL The list of criteria goes on and on! The best way to ID these guys is to have it directly in front of you so that you can pick out all the details.> The little crab is in a 3 gallon exile tank <Good> with the Emerald Mithrax crab the store guy told me would be great (great at picking at my star polyps as it turned out). <Yep, that's annoying for sure!> The crabs seem fine but haven't run in to each other yet. <Very good. I'm so glad to hear that he's got a good home. Many of these neat little creatures end up being disposed of and that's a real shame.> Now, that I know someone may be able to help in my new foray in to saltwater, I have a few other unidentified thingamabobs in my tank. One has appeared out of nowhere and grown really fast in under a week. In fact, I didn't even notice it until about three days ago, and it's doubled in size. <Yowza!> It's attached to the live rock under my favorite hitchhiked feather duster. The base is a little fuzzy. The stalk is pastel yellow, almost like a crayon. It has no real mouth, arms, or legs or anything but it is growing. I will have to get a photo. <Please do, I'd love to see it.> It looks like it's calcareous. Today, the tip changed in appearance to have a rectangular-shaped protrusion. It kind of curves up at the end. I'm guessing it's either a strange yellow algae or perhaps a fungus (are there freshwater funguses?). <Sure, there are marine versions as well. Fungi are everywhere. I'm thinking that what you have though could be a Poriferan/sponge of some sort (would need to see a photo). The neat thing about these guys is the diversity of shape and color that they come in. It's truly amazing. For more information/photos, please see Bob's pages regarding sponges, starting here (3 pages): http://www.wetwebmedia.com/sponges.htm . Be sure to check out the associated links at the top of the link as well!> The little feather duster really doesn't like it since it's in its space! I'm wondering if I should bust it off. <Hmmm, well it depends. If it is indeed threatening something you like, you could attempt to remove the offender (although if it's a sponge, many times they simply grow back). If you do (and in case it's a sponge), I'd remove the rock from the tank first. I'd take it out, scrape away as much of the offender as possible, then scrub the area with a toothbrush, and rinse *well* with tank water (into a bucket or similar). Also, you might want to check your nutrient levels/nitrates. The organism's rapid growth could be an indicator of such. In the meantime, if you can get us a photo, we'll see if we can't narrow down/confirm what you've got there!> Thanks again. <You bet. Take care, -Lynn>

Update Re: Hitchhiker Crab, Plus Possible Poriferan, Macroalgae -- 7/30/08 <Well hello again!> Ok, I threw up some photos quickly since I'm low on time. <Appreciate it!> Photo of the entire 12 gallon nano cube showing where the "thing" is: http://www.fishpondinfo.com/photos/other/other/temp1.jpg <Nice looking system.> Photo of the thing a few days ago when it grew fast and was yellow. My favorite little feather duster is open to the right of it.: http://www.fishpondinfo.com/photos/other/other/temp2.jpg <Neat> Photo from today of it with the feather duster, Zoanthids, xenia, macroalgae, etc. When I came home, the thing had turned green!: http://www.fishpondinfo.com/photos/other/other/temp3.jpg <Ah yes, that helps. It looks like some sort of macroalgae, possibly in the genus Halimeda (a calcareous algae). We should be able to tell when it gets a bit farther along (if it's that or something else). Here are some links re: http://www.wetwebmedia.com/greenalg.htm  http://www.reefkeeping.com/issues/2004-04/nftt/index.php  Good photos here: http://www.reefcorner.com/SpecimenSheets/halimeda.htm  It definitely likes the light. <Yep> There were no sponge matches on the site you gave me but fan sponges seem to come the closest. Is that what it is? <Don't think so.> The feather duster has bent itself off to the right to avoid bumping in to this thing that I swear wasn't there at all a week ago! <Funny how things spring up like that isn't it! It's a matter of conditions becoming favorable for the organism's growth/survival.> I put in about 15 ml.s of RowaPhos weekly in a little mesh bag to keep the phosphate low. I use RO water. It takes over two hours to make 3 gallons once a week. <Yikes. That sounds like an awful long time to make just 3 gal's of RO water (is it RO only or actually RO/DI?). Here are some contributing factors to low production: a connection/plumbing problem, small unit, clogged/exhausted membranes, very cold water, or low water pressure. Just for comparison, I have a Typhoon III (75 GPD) RO/DI unit from AirWaterIce that takes about 45 min's to make 3 gallons. That's with the (tap)water pressure at about 68-70gph. In the winter when the water is in the fifties(F) it takes about an hour instead. I'd go through the above list and see if anything pops.> I don't know how those with large tanks do it; they must run the RO all the time which I'd be afraid to do (leaks, wasting huge amounts of water; we're on a well). <Ah, I see. Have you checked the TDS (total dissolved solids) level of the well water? If it's really high, you may be exhausting/clogging the membranes pretty quickly. That would definitely slow things down.> Here are two other photos if you can confirm what I think they are: Pineapple sponge? http://www.fishpondinfo.com/photos/other/other/squirt.jpg <Ding, ding, ding! You are correct. It's a harmless/beneficial little Syconoid sponge, aka a Pineapple or Q-tip sponge.> Sponge of some sort (the yellow thing at the top of the rock)? http://www.fishpondinfo.com/photos/other/other/sponge.jpg <I can't quite tell, but yes, it could be that or one of several other harmless organisms, like a Bryozoan.> Thanks again! <You're very welcome! Take care, -Lynn>

Re: Crab ID   -07/18/08 <Am sending this mystery to our fave ID'er... Lynn... stay tuned... BobF> WooHoo - fave ID'er! Thanks Bob! I actually saw this query last night but didn't grab it because I knew I wasn't going to be able to send a reply until later on this afternoon or tomorrow. I've had a couple of things come up that I need to tend to, but I'll dig in as soon as I can :-) Take care and have a great weekend! -Lynn <Thank you Lynn... not just being lazy... am away from ref. works! Cheers, BobF> <<LOL Lazy is a term that I would never associate with you! I can't imagine having your schedule - or workload! I left that query in case someone else had the answer(s), but I'd already planned to nab it this morning if it was still unanswered. You know I'm always happy to take the critters! :-) Hope you have some fun plans lined up for this weekend. We're having some friends over tomorrow night for dinner and mucho Tequila. Wish you were in the neighborhood! Take care, -Lynn <Ahh, tah kill yah! Very good ones (triple distilled) are faves of many folks in the livestock whlse. trade for some reason... The smell always seems to remind me to roll up my sleeve... Cheers! Kanpai! Twenty three skidoo, and pass me the aspirin. BobF>
Crab ID: Likely Xanthid -- 7/18/08
Dear WWM Crew, <Hi Kevin> We bought a very small piece of live rock...and now have two very large pain in the glass hitchhiker crabs. They are not large...just large pains. <They certainly can be!> I think one of them ate the arm off my starfish...hmmm. <Oh, not nice at all.> I have included a photo here as it seems you have had someone ask about this crab before, but their photo was very blurry and I cannot tell. Questions are: What type of crab is it? <Looks like a Xanthid (Family Xanthidae) of some sort. I'm sorry I can't be more specific.> What should we do with it? <I would find it another home.> The second crab...is also hairy like this one but more "spiny." However, I cannot catch him...seems like some late nights are ahead. <Been there, done that! If/when you do get him out of there, please do send along a photo and we'll take a look at it. Also, if you know where the rock came from, that would be great.> Thanks, <You're very welcome. Take care, -Lynn>


Strange Crustacean: Need More Information - 7/11/08 Hi. My name's Brian, <Hi Brian, Lynn here this afternoon.> ..and I recently went to South Padre for the second time, <What a great place that is!> ..and once again I caught this strange crustacean. I caught one on my first trip to SP and spent days trying to identify it on the internet but never found anything, and the same thing this time...I Googled "sand flea", "sea lice", South Padre crustaceans", but could never find what I was looking for. <Yep, that's frustrating.> It surely can't be a new species because I saw several of them and I can't be the only one who's come across one. But anyways, the crustacean looked somewhat similar to a horseshoe crab. It was about 1 inch long with a thin tail that was a couple of inches long. It was a pale white color, had several overlapping segments to its carapace, and I couldn't find any eyes on it. On the bottom it had, I believe six legs, and each leg was like a small crab pincher. Please help me identify this creature...I really really REALLY wanna know what it is! <Me too! In all the years I've been going to the Texas coast, I've never seen anything quite like what you've described. I looked around, did some research and finally asked a nice fellow from the Natural History Museum in Los Angeles for some help. Unfortunately, he needed more information. He said that what you saw could be anything from a dead Mole crab with its thin abdomen extended out behind it, to a large isopod of some sort. Here's a link that shows a bit more regarding Mole crabs (Emerita spp.): http://www.diatribune.com/marine-life-series-mole-crabs . The creature also sounds a bit like a Cumacean, but I've never heard of one that large and besides, they have more than 6 legs. Here's a link with more information regarding Cumaceans: http://en.wikipedia.org/wiki/Cumacea. Unfortunately, at this point, I'd really need a good close-up photo in order to have any chance at getting an ID for you.> I wasn't able to get a very decent picture, the one we got is blurry, and my step-dad isn't letting me have it for some reason. <Well Brian, the next time you go back to Padre Island be sure to look around for more of the little critters. You might want to see if your camera has a 'Macro' mode/setting, usually indicated by a small flower or daisy-like icon. In macro mode, you should be able to get some good shots. At that time, please do send them along. I'd love to solve this little mystery! Take care, -Lynn>

Re: Strange Crustacean: Likely Mole Crab - 7/11/08 Hello again. <Hi Brian!> So this time I've included a picture, it's still blurry but it was the best one out of five, and in conjunction with my description you can see a little better what I was talking about. <Yep, thanks for sending that along. It makes all the difference.> I looked up more pictures of both of your suggestions, and I think the creature I caught was likely some kind of mole crab <I agree. It definitely looks like a Mole or Sand crab of some sort -- something in the Superfamily Hippoidea, possibly in the Family Albuneidae.> ..(although it wasn't dead, because it was crawling around in my hand), the only difference was that most of the pictures I found of mole crabs didn't have the long thin tail I described (which you can make out in my photo). <Interestingly enough, I've seen Mole crabs that look very similar. The only difference is that what looks like a tail is actually a pair of antennae on the head. Take a look at this photo: http://www.dnr.sc.gov/marine/sertc/images/photo%20gallery/Albunea.jpg . At first glance, it looks like the narrower end on the right *should* be the head, but it's not. It fools the eye a bit. Here's another link with more information on Mole crabs in this Family: http://www.crustacea.net/crustace/anomura/www/albunei.htm. They're neat looking little critters, aren't they!> But for now, I'm going to assume that I caught a mole crab....but let me know if you have any other opinions. <I think we've got it!> Thanks for the help. <You're very welcome and thanks again for sending in the photo! Take care, -Lynn>

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