Red Claw Crab Help?

[Wiggins]

I bought 2 red claw crabs about 3 weeks ago (one male and one female). They were both healthy, got along well and active until today. When I arrived home I checked the tank and the male was on his back stiff with his abdomen flap kind halfway open. I checked the rest of the tank to see if it was a molt but it wasn't. I put him in a separate tank and hand fed him peas. He ate them but after a few hours he flipped on his back again and hasn't moved since then. I keep assuming he is dead but whenever I go near the tank he flinches so I guess not. I have never seen either of them molt before and I just don't know what to do with the male.

The female during this time was perfectly fine then when I removed the male from the tank she started to flip upside-down... I went to feed her and usually when I remove the tank lid she hides under one of the decorations but today she sat perfectly still on top of a branch literally 2 inches away from my hand.

So my real question is.. What's going on with my crabs??
Any type of feedback would be very helpful!

 

[cornflakes]

I'm not sure but I might as well ask:

-water temp?
-freshwater or brackish water?
-land to water ratio?
-what do you feed them and how much / how often?
-sometimes they may fight and sustain injuries (my larger female RCC had attacked my smaller male RCC and his arm was 85% torn off after she grabbed his arm).

 

[Wiggins]

The water temp stays around 70-75.
I keep them in fresh water, and I have a 29 gallon tank with sort of a beach set up (sand sloping down to transition into water) I also have a large piece of drift wood and a bunch of plant ornaments for them to climb and play on. I feed them once in the morning and once at night I usually make sure that they've both eaten at least 2-3 bloodworms each. When I bought the female she was already missing a claw but they never seemed to fight.

 

[Wiggins]

Also, the males abdomen flap keeps opening and closing.. What is he doing?