freshwater crabs

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doozie01

Feeder Fish
MFK Member
Jun 25, 2007
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I was just at my LFS and I saw some freshwater crabs. I was wondering if they are hard to keep. Do they get very large? Will they pick at my other fish? How big do they get? etc. Anything you can tell me would be great. I would google them but I've got a crazy week and I'm just looking for some quick info to see if I want to research more. Thanx.
 
well crabs do need to get out of the water to breathe air so they're not really a good addition to an aquarium. Also they will pick at fish. that's not saying they can actually catch and kill them but, given the chance, they will.
 
What kind of crabs were they? As far as I know there are no actual FW crabs. There are brackish/marine crabs that venture into FW, but none that should specifically be kept in FW.

Just about all fish stores sell some crabs labelled as freshwater, and they're always brackish.

You must find out the specific species before you can figure out care.
 
ShadowBass;1114575; said:
What kind of crabs were they? As far as I know there are no actual FW crabs. There are brackish/marine crabs that venture into FW, but none that should specifically be kept in FW.

Just about all fish stores sell some crabs labelled as freshwater, and they're always brackish.

You must find out the specific species before you can figure out care.
thanks
 
I just got to reading and apparently there are a couple of FW crabs. News to me, but I haven't read up on it in a long time.

See if you can track down the actual species, but they're still most likely a brackish crab since that's what's commonly sold as "freshwater". I've yet to see anything at any fish store yet that's anything but the common brackish/marine species.
 
Few show up in the aquarium trade, but there are several exclusively freshwater families of crabs, and numerous freshwater representatives of generally brackish or marine groups (many in this second category require salty water for larval development). Air access requirements vary, but some remain submersed their entire lives. ... All in all, a few hundred species. Additionally, some "land crabs" (Gecarcinidae) lead semi-aquatic lifestyles.

See this page for some images and background info on some colorful Southeast Asian species.

A map of world distribution for the first variety is found here. More info at http://www.nmu.edu/biology/Neil/MainFWC-website/FWCHomepage.html.
 
Most crabs need a platform to reside on. Much the same as a turtle.

They have fiddler crabs at my LFS that are $7 each and 2-3" across. They may pick at small fish, slow fish, long finned fish. However, other large fish such as cichlids might see them as a food item.
 
We had a few crabs early on before switching to crayfish. We never had any fish small enough that they could bother but when they molted the fish had a crab dinner. Compared to crayfish....crabs are stupid and unintresting.
 
There are several types that vary widely in size, I kept some little brown ones that kept climbing the curtains behind the tank.
 
Fiddler crabs (Uca spp.) and redclaw crabs (Sesarma spp.) require brackish water and air access (paludarium setup or protruding decorations) to be healthy.

Malawi blue crab, Potamonautes orbitospinus (aquatic):

crusta10_142_Potamonautus%20orbitospinus.jpg

(Crusta10.de)

potamonautes_blue_crab.JPG

(OhiExchange.com)
 
MonsterFishKeepers.com