RED CLAW CRABS ARE FRESHWATER! THEY NEED ACCESS TO THE SURFACE SO MAKE A SAND SLOPE OR SOMETHING FOR IT TO GET TO! CRAYFISH WITH CRABS ARE ENTIRELY OK! IF YOU SEE YOUR CRAYFISH TRYING TO ATTACK THE CRAB OR ANYTHING ELSE NEAR HIM ITS NOTHING MUCH JUST THE OLD GROUCH SCARING THE CRAB OR FISH AWAY FROM HIM! NOT BEING SUCH A JOLLY OLD CRUSTACEAN THATS ALL