red claw crab with eggs    red claw crab

Sesarma Bidens

(Red Claw Crab, Red Clawed Crab)

Care Level: Moderate
Tank Conditions: 72-82°F; pH 7.5-8.0
Temperament: Peaceful
Max. Size In Aquarium: Up to 2.7"
Diet: Omnivore
Family: Sesarmidae

The Red Claw Crab gets their name from their bright red claws. These crabs are usually sold as freshwater crabs. From what little Red Claw Crab care information I could find on the internet, it seems that they are actually brackish crabs. My tank is a brackish tank with a salinity of 1.004. A ph of 8. I use Reef Crystals salt mix. I have talked to several people on some forums that have tried to keep them in fresh water and had no luck long term. So if you want to try these crabs, I would recommend brackish water. When I purchased my Red Clawed Crabs, 1/11/03, I floated them for 3 hours to slow get they adjusted from the fresh, 7 ph pet store water to my brackish 1.004 ph 8 water. The 2 Red Claw Crabs live with 4 Bumble Bee Gobies. I was afraid that the crabs would bother the gobies, but so far I have not had any problems. I keep the crabs well fed.

The Red Claw Crabs eat about anything that settles to the bottom on the tank. I feed them sinking wafers, algae wafers, shrimp pellets, frozen bloodworms, and frozen mosquito larvae. I have found out they will eat some plants. I placed a small amount of Java Moss, Corkscrew Vallisneria, Duckweed, and Brazilian Waterweed in the tank. All which were eaten by the crabs. I have some Java Fern and Cryptocoryne Wendtii which the crabs have not touched yet. I have fed my crabs peas, which they will eat. The crabs would most likely eat other vegetables. The crabs will also eat snails. I placed a 1/4" pond snail in with the crabs and found the shell empty when cleaning the tank. I place my extra Apple Snail egg clutches in the tank also. And speaking of cleaning the tank. Make sure you have very good filtration with the crabs. I have noticed that the crabs are very dirty.

Being that crabs are crustaceans, as they grow they will molt. This is where the crab sheds its old exoskeleton, or shell. The crab will be vulnerable after his molt till his new shell hardens. Molting is a very stressful period for crabs, and they might die under the stress.

The driftwood in my tank is above the water line. The crabs need access to air. The crabs will craw up the driftwood and hang out above the water for hours. Make sure that the top is completely covered, they are good escape artists. These crabs will quarrel among themselves, so be sure each one has enough room and don't crowd too many in the same aquarium. House no more then 2 Red Clawed Crabs in a ten gallon tank. The tank should provide several hiding places for the crabs.

red clawed crab tank

It appears to me that sexing of the Red Claw Crabs is as follows. If you look at the picture on top of this page you will notice that the crab on the right has more developed claws. I believe males claws are larger. The female is the one on the left with the less developed claws. The photo also shows an egg mass she is carrying. I noticed the egg mass on 6/4/03. From what I've read on the fry, when born simply drift through the water. Raising the fry, is extremely difficult if not impossible. They will need very specialized tiny foods that are not easily obtained, and the fry can be so small they are almost, if not totally, invisible to the eye.


red clawed crab