Let me begin by stating I know NOTHING about crab anatomy....other than the 2 pointy things hurt when they get your finger
Anyways, my emeralds are very friendly and in view most of the time. Today, my larger one was perched up on a rock with the rear, bottom "plate" on it's body unhinged and hanging down. It looked red on the inside with a few "vanes" fanned out. It appeared to be cleaning inside there with it's claws. What exactly was it doing. Ran to get the camera but the plate was closed by the time I got back. I have a feeling it was reproduction related, but curiosity has taken hold and I want to know what it ws doing.