What the heck is my emerald crab doing???

[jonboyb]

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.

 

[Fluff]

It does sound like she may have been prepping for eggs. You should know if a few days when you see her carrying around a red "raspberry" type lump underneath. Unfortunately though, the babies usually get swept up in the equipment or food for whatever else is in the tank but it's still an neat process to watch.

 

[jonboyb]

I never had a clue their "undershields" moved...LOL. I thought they were pretty much fully attached, so I freaked out a little when I saw this. My 2 emeralds were my first critters long ago. They've not been ideal citizens, taking down a couple of peppermints and a nassarius snail or 2, but so is life. Haven't had the heart to banish them to my mantis tank since they've been around since the beginning.

Can mithrax crabs breed in the home aquarium? I only ask because a few months ago I had a baby crab outbreak (too small to ID them) but they vanished pretty quickly. I've only seen a couple of them since then, although the 2 I've recently noticed do appear to be emeralds. I had always chalked it up to hitchhikers.