HCA: Hermit Crab Association

I have two red claw crabs, I looked in the tank and I was pretty shocked to see what I thought was a 3rd one, so I asked my husband if he got another one and he said no.. Then I realized he molted. Soooo... are they suppose to eat their exo like hermit crabs? And are they suppose to be in fresh water or salt water? If no one has an answer I'll just call PetSmart but it's kinda creepy looking at the exo and if it's not useful for them in any way, I'd like to get rid of it ASAP. lol

They will eat it to regain minerals, although the others in the tank may get to it first. It is really creepy at times - my fids can go for a week before finishing it off, and meanwhile there's this pale white ghost crab floating through tank - but it's extremely important nutrition for them.

They are just as aquatic as my fids, and they should have a large filtered and cycled brackish tank to spend most of their time in. They are estuary critters and they do need low brackish water to be healthy - they aren't going to be able to do as well if they're having to choose between full salt and full fresh. (Brackish water needs to be made with marine salt, and it should be around 3 Tablespoons per gallon.) It should be maintained like a cycled fish tank since they will probably spend a good 90% of their time in there and bad water will cause gill damage.

I would not trust Petsmart in the LEAST with information about these guys! They also sell true fiddlers as "freshwater" that "don't need land". And of course look at the info they give out on hermit crabs, and on most fish. It's better to look at outside sources for care information as the majority of pet stores are going to want to make a sale more than get the animal into the proper home.

Thank you for the information after I posted this I did a quick search because I wasn't sure if anyone would answer, and I read that most red claw crabs don't eat their exo so I threw it away Wish I didn't. So I need to get salt water for them? I've been using fresh water and I have a huge rock that they can climb on for now.

They need brackish water, which is made using the the same marine mix you use for the hermit crabs but at about half the strength. It's about 3 tablespoons of the salt mix (Instant Ocean or Oceanic - they all use the same amount) to one gallon of water to give you a specific gravity of around 1.008. ("Specific gravity" is the term used to measure how salty the water is, it's not something that has to be specific.)

Brackish water is what happens when a freshwater river means the salty ocean - it's not quite fresh, not quite salt, but somewhere right in the middle. The good thing is that with brackish species the water never has to be exact, so you can get away with "around 3 Tablespoons" instead of having to measure it out exactly.

So pretty much just half of what I'm suppose to originally use, correct? Do they need a certain amount of space? I currently only have them in a one or two gal. container. I may just end up getting rid of them my husband bought all of them on impulse and I'm the one who ended up taking care of them. I'm keeping the hermies tho their addicting.

I'm not completely sure - everything I'm seeing is recommending a 10 gallon.
http://badmanstropicalfish.com/profiles/profile101.html

(Someone had been able to captive breed these guys! How cool is that. http://www.aquahoito.info/sesarma/index.html )

wodesorel wrote:(Someone had been able to captive breed these guys! How cool is that. http://www.aquahoito.info/sesarma/index.html )

That was a great read!

wolfnipplechips wrote: That was a great read!

I was thinking about sending it to you directly, but I wasn't sure since they aren't hermits. Not the same species, but I think sometimes it's nice to read about others who have tried to breed something that is considered "impossible"!

Does anyone know how (anti)social these guys are? I want to build a paludarium type thing in my 20 long just as a project, but part of the planning stage is figuring out what I want to put in there, and red clawed crabs are on the shortlist. The tanks is 30 x 12, minus a little floor space for the wall that will provide their dry dock. It would be cool if I could get 3 or 4 in there, but if I can't do at least 2 then I'll look for something else. I've seen a lot of sites that say 1 crab needs 10 gal min, but haven't been able to find out about multiples.
Or would fiddler crabs be a better choice if I wanted several of them?

I believe they're the same as fids in that a harem of females is perfectly safe with each other and it's only the males that will fight and kill each other. So if you did one male and 2 or 3 ladies you should be fine! I've got two dozen fids (there are either two or three species, having trouble telling minax and pugnax apart) in a 29G palludarium and as long as there is only one mature male at a time they are fine and happy with all the company. I just kept watch on how they were doing in a group and added more female crabs as I felt comfortable with them being accepting of the numbers. So far they are all doing great.

Red claws are supposedly much more into eating other live animals that fiddlers are, so be cautious with tank mates! Being brackish also severely limits what you would be able to add as anything aside from guppies would either get too large for a 20 gallon or would make a meal of the crabs. Not sure what your plans were for your tank aside from the crabs.

So fiddlers are all fresh? That does make things easier. My daughter like pictus catfish so I wouldn't be opposed to getting a couple of those, and I've always liked cardinal tetras, so maybe a few of those would be good to get something that will spend a little time more than an inch above the bottom! (I haven't gotten to the researching tank buddies stage yet because I haven't actually committed to red claws, but I would try to avoid anything that would be eaten by anything else if I didn't intend for it to be that way). It does kinda sound like fiddlers would be lass of a hassle... new google search!

This idea may be outgrowing a 20 gallon tank, but if it all comes together in my head I might put my 40 gallon up for it.

No, all fiddlers are brackish as well. There are no freshwater crabs for sale that aren't nearly full-land dwelling. (And cannibalistic and will eat anything they're put with.)

There are some shrimps that are freshwater though! Crayfish are as well, but again they'll eat any tankmates they're housed with.

OK, I get it, it's either crabs and a very small selection of fish, or fish. Gotcha! Like I said, early research stages here, thanks!

Hookie wrote: Like I said, early research stages here, thanks!

Yeah, the research bit is kind of a bummer. I know I was all excited when I got my 29 and thought I had it all planned out, and then I learned what I wanted was either too large to keep in there, or wasn't available in my area. I really hated the idea of guppies and was pretty unenthusiastic that they were my only option, but now I am absolutely in love with them and I wonder how silly I had to be to say that I didn't like them!

Great places to research:

http://brackishfaq.webspace.virginmedia ... shfaq.html
(Neale is considered a brackish water guru among the fish communities and I always head his advice!)

http://www.wetwebmedia.com/brackishsubw ... bIndex.htm
(He's also at Wet Web Media, which is a place for people to write in for answers and advice. The FAQs and Archives are a headache to read through, but you can learn so much from it!)

http://badmanstropicalfish.com/brackish/brackish.html
(Badman's is another well-respected resource though the information is older.)

Awesome, I have several empty tanks, and I know I want some fish, and I also want to do a couple of projects that interest me, in particular a paludarium with a drip wall and live plants, which wouldn't really work with brackish water. I was trying to come up with a critter that would take advantage of the paludraiumness, but frogs don't excite me, and the critter would be kind of secondary to the project, rather than the focus. I have a vision of a grand master crabifishitat that I'm going to build someday, so for now I'm doing smaller experimental units to test out certain features I'd like to put in. Thanks a bunch for the reading assignments!