The Red Claw Crabs: An Update

[sophiegackowski]

As some of you will know, after setting up the tank and getting the crabs, everything went a bit pear shaped. I had bought four for a 36 litre tank, with rocks creating many little crevices, cracks and caves for them to hide in, and an area for them to come in to the open air. I do not agree with the notion that the crabs are territorial in the sense they need a certain amount or area of land each: for these crabs continously gathered to the same point, fighting for the same cave, even though there was one of the same size on the opposite end.

I am not a cruel person and did not deliberately throw four crabs in knowing they would fight like this, indeed I was told by some lfshops to take as many as eight which I completely refused, thinking four (if I was to get three females and a male) may live quite harmoniously. I was told the females were less agressive and territorial. Anyway, no choice in that! I've been given three males and a female, but having observed them for many hours I have seen the female is as snappy as the rest of them, often chasing the bigger ones depsite her size, so perhaps any gender would react this way, not just males.

After the initial half hour in their tank, in which I sent my last post, I took action and grabbed brand new plastic plant pots (free from pesticides, washing up liquid etc) and cut small doors into the front. I placed three of these in, as well as the many caves, and the crabs calmed down, claiming the plant pots for themselves . There appears to be one dominant male who does "rounds" of the tank, chasing the others and making sure they are in their right place. There have been no casualties: they simply try scare each other off, but it is nonetheless a terrible set up in my opinion, not due to actual violence but due to the assumed stress this may be causing them.

The crabs appear to search out and pick up piece of excrement, aiming to put it on another crabs head. This again must be a sign of dominance, something I have never read about in my research. They also flash their undersides to each other.

They eat, ALOT, and in turn poo alot. I had live plants in there due to my initial set up of the tank, in which I didn't know what animals I would be getting, and they are slowly but surely getting through them.

The PH was not high enough for the crabs, and I found a couple of handfuls of coral sand has raised this, a little tip for anyone thinking about keeping these crabs.

Yesterday they hadn't ventured out of the water, but today they seem to be taking turns to sit on the rock for fifteen minutes or so. They are very active, I haven't seen any of them stay still for more than five minutes.

The shop I got them from has decided to shut today...which would just be my luck, but I plan to take two or three of them back first thing tomorrow. I'm deliberating whether to keep one male and one female, or just to keep one or the other.

I just thought that it would be helpful for people to learn of my experience, as opinions and views on these creatures vary. I have found that the care leaflets on the internet are either humorous or uninformative: which doesn't help much. Here's a quote from a repeatedly cited website:


If you want to see these crabs in action, you need to keep several in spite of the “two per ten gallon tank” rule that appears in public parlance. Fuhgettaboutit. Live life on the edge. Put a half dozen in there and enjoy. - http/aqualandpetsplus.com/Bug,%20Red%20Claw%20Crab.htm

Yes, you may very well see them in action, but I can't imagine it would give you much pleasure unless you enjoy seeing crabs fighting. Mine have calmed down as I said, and for the most part are leaving each other alone, going about their business be it eating, climbing (they love to climb) or sitting chilling out on a rock. I'm not going to risk moulting time though - I don't even want to know what they would do.

Again may I add that I feel I should inform people of this experience in order for people to have more information at hand and not to have any nasty surprises. Any feedback or comments are welcomed.

 

[nmonks]

Does sounds as if you're having quite a time there with your red-claw crabs!

Nothing much to add except that the Aqualand Pets Plus web site is one that regularly gives me the shivers. I've read a few of their pages over the years, and at best they're old school, and at worst downright misleading and/or cruel. I've tried writing to them in the past, but never heard anything back. They frequently recommend the use of feeder goldfish, routinely recommend too-small aquaria, and appear to have no idea about water chemistry; consequently, their web site is not one I'd ever recommend as a source of information. Quite the reverse in fact; in many ways they seem to be precisely the type of shop that gives local fish shops a bad reputation.

Cheers, Neale

 

[kewskills]

I have thought of getting some of these but judging by your experience, these appear to be a pain in the #### to keep in a good way, especially in a relatively small space.

 

[nmonks]

If you want to keep crabs, the best ones are fiddlers (Uca spp.). Although more picky about water chemistry, needing at-least brackish water conditions without fail, they are much less aggressive. Or more specifically, aggression between males is mostly display: they wave their claws at one another until someone backs down. Since males are easily sexed by having that one giant claw, keeping a boy and a couple of girls is no problem. They mix well with mudskippers of similar to slightly larger size.

Cheers, Neale

 

[kewskills]

Cheers for the advice Neale, Water chemistry is not a problem to keep OK, I shall look into these little fellas. I like the sound of their fighting technique, just waving at each other and no damage. sounds funny to watch.

Karl

If you want to keep crabs, the best ones are fiddlers (Uca spp.). Although more picky about water chemistry, needing at-least brackish water conditions without fail, they are much less aggressive. Or more specifically, aggression between males is mostly display: they wave their claws at one another until someone backs down. Since males are easily sexed by having that one giant claw, keeping a boy and a couple of girls is no problem. They mix well with mudskippers of similar to slightly larger size.

Cheers, Neale

 

[sophiegackowski]

We don't appear to have any fiddler crabs around this area, and I'm not keen on the idea of getting crabs posted to my door! I wish I'd had the oppurtunity to actually see these crabs in action - it was all information and stories but because I ordered them in from a lfs and they weren't already there, I didn't have the oppurtunity.

I changed some of their water this morning, it's looking as though it may take more than a weekly change to keep up with them. They're dirty little buggers!

I noticed also that one of them I had been given only had seven legs - and it seems to be this one that fights. If you see a crab in the shop with a limb or two missing you might want to consider whether it thinks itself as boss! I've also unfortunately noticed that another one is missing a leg, no doubt been chopped by th big one overnight They're currently eating algae wafers: I put a couple in but it just caused mayhem, so they had to have one each! I'm planning on keeping them entertained this way until the morning, by which time I'll only have one or two and keeping up with the tank, and the resulting mess, will be easier.

In all honesty, I would strongly put out to everyone that to set up a tank for red claw crabs with the exact conditions, you're going to have to cough up for marine salt, a hydrometer, test strips, Ph boosting substrates, costly hidey holes and a decent filtration and heating system. All in all, I think that they're maybe not the best for beginners, and from what Neale has said: think about going fiddler instead.

I've heard that the rcc's live in large colonies/groups in caves etc - but I dare say there's no-one around to report on their aggression in the wild.

I'm thinking about making up a report on them and posting it somewhere: an honest experience I think it may be beneficial to people.

 

[kewskills]

Shame you have to get rid of some, however keep up the good work of keeping us all posted on your future experiences with these

Cheers, Karl

 

[iliveinazoo]

I would suggest that mixing mudskippers and fiddlers is risky business since my crabs were left with a couple of legs and one was left with only one eye - they would have died if we didn't witness the attack and move them out straight away. The skippers were bigger but not by much - they are the Barburus species which might be the reason why the crabs didn't stand a chance.

 

[nmonks]

Correct. As I've written elsewhere, P. barbarus has to be kept "in solitary" -- even amongst themselves males fight to the death. When mixing Uca species, you need to choose other small, non-aggressive mudskippers, like the Indian Dwarf Mudskipper for example.

Cheers, Neale

they are the Barburus species which might be the reason why the crabs didn't stand a chance.

 

[jrobinson200]

hi, ive just gotten 2 male red claw crabs and so far so good. only had them 2 days, they have a nice set up, big tank for the 2 of them, 1/4 land, rest under water with one big piece of bogwood sticking out of the water too. they love picking at this and also the live plant that is in there. they seem fine with each other at the moment but are only 7 weeks old, will have to see how they go!

 

[kizno1]

sorry to hyjak but
can these be kept in freshwater? my lfs says they can but i always thought they where brackish and just being mis sold. are mudskippers brackish aswell? i saw some a few days and was thinking about looking into getting some.

 

[jrobinson200]

sorry to hyjak but
can these be kept in freshwater? my lfs says they can but i always thought they where brackish and just being mis sold. are mudskippers brackish aswell? i saw some a few days and was thinking about looking into getting some.

they are sold as freshwater but from the majority of the research ive done they should have slightly brackish conditions so i have added a slight bit of marine salt

 

[kizno1]

yh i always though they would be and the lfs was just trying to make more money by saying there freshwater. thanks

 

[grayshark1956]

As some of you will know, after setting up the tank and getting the crabs, everything went a bit pear shaped. I had bought four for a 36 litre tank, with rocks creating many little crevices, cracks and caves for them to hide in, and an area for them to come in to the open air. I do not agree with the notion that the crabs are territorial in the sense they need a certain amount or area of land each: for these crabs continously gathered to the same point, fighting for the same cave, even though there was one of the same size on the opposite end.

I am not a cruel person and did not deliberately throw four crabs in knowing they would fight like this, indeed I was told by some lfshops to take as many as eight which I completely refused, thinking four (if I was to get three females and a male) may live quite harmoniously. I was told the females were less agressive and territorial. Anyway, no choice in that! I've been given three males and a female, but having observed them for many hours I have seen the female is as snappy as the rest of them, often chasing the bigger ones depsite her size, so perhaps any gender would react this way, not just males.

After the initial half hour in their tank, in which I sent my last post, I took action and grabbed brand new plastic plant pots (free from pesticides, washing up liquid etc) and cut small doors into the front. I placed three of these in, as well as the many caves, and the crabs calmed down, claiming the plant pots for themselves . There appears to be one dominant male who does "rounds" of the tank, chasing the others and making sure they are in their right place. There have been no casualties: they simply try scare each other off, but it is nonetheless a terrible set up in my opinion, not due to actual violence but due to the assumed stress this may be causing them.

The crabs appear to search out and pick up piece of excrement, aiming to put it on another crabs head. This again must be a sign of dominance, something I have never read about in my research. They also flash their undersides to each other.

They eat, ALOT, and in turn poo alot. I had live plants in there due to my initial set up of the tank, in which I didn't know what animals I would be getting, and they are slowly but surely getting through them.

The PH was not high enough for the crabs, and I found a couple of handfuls of coral sand has raised this, a little tip for anyone thinking about keeping these crabs.

Yesterday they hadn't ventured out of the water, but today they seem to be taking turns to sit on the rock for fifteen minutes or so. They are very active, I haven't seen any of them stay still for more than five minutes.

The shop I got them from has decided to shut today...which would just be my luck, but I plan to take two or three of them back first thing tomorrow. I'm deliberating whether to keep one male and one female, or just to keep one or the other.

I just thought that it would be helpful for people to learn of my experience, as opinions and views on these creatures vary. I have found that the care leaflets on the internet are either humorous or uninformative: which doesn't help much. Here's a quote from a repeatedly cited website:


If you want to see these crabs in action, you need to keep several in spite of the “two per ten gallon tank” rule that appears in public parlance. Fuhgettaboutit. Live life on the edge. Put a half dozen in there and enjoy. - http/aqualandpetsplus.com/Bug,%20Red%20Claw%20Crab.htm

Yes, you may very well see them in action, but I can't imagine it would give you much pleasure unless you enjoy seeing crabs fighting. Mine have calmed down as I said, and for the most part are leaving each other alone, going about their business be it eating, climbing (they love to climb) or sitting chilling out on a rock. I'm not going to risk moulting time though - I don't even want to know what they would do.

Again may I add that I feel I should inform people of this experience in order for people to have more information at hand and not to have any nasty surprises. Any feedback or comments are welcomed.

I just found your post and it was so interesting I had to write: I had RCC's in my tank with fish, never had a problem. I decided finally to get second tank, which I did. Now they are in the right environment, I'm sure the fish are happier, but, I did find too much misinformation and conflicting advice on how to care for this type of crab. The store said they don't add salt, told me I could add aquarium salt. I find out later they need brackish water (I originally found them by accident in the store one day when I was looking at all their fish tanks) and thought they were interesting, so I bought several. My tank has sand at one end, pebbles at the other, a large piece of driftwood, rock caves, tree house, live plants, heater, and I just added a small terra cotta pot so they have an additional hiding place. I have lots of different food for them, a very tight lid, and am wondering what in the heck they do at night while I'm sleeping?

Have you ever had the experience of finding one in your tank at night using a flashlight and finding him bright cherry red? I did! Does the color change indicate anger? stress? mating ritual? maybe he is tired of shark week reruns, I don't know, but he was bright lipstick red! I have not seen one do that since. I don't know if mine are males or females (I probably have both, the store doesn't know) and I'm now thinking of other objects to put in the tank so they can share their territory better. They seem to get along but I suspect some of them don't, like when I'm asleep. Only other thing I can add is a wood bird ladder that I can attach to inside and they can climb on that. I may get a cconut hut or something for them. Any suggestions would be appreciated. Thanks!