Adam at the lab
I put my new, precious, soft-shell female into the tank with two males and some herring (you know, in case they wanted a snack...) and started taping. Things were really slow for the first 6 hours, then things got crazy!
The small crab is the female, playing the edible rope in a medieval tug-of-war: the old-shell male (with white barnacles attached to his back) ate 2 1/2 of her legs! Don't worry, I took her out and put her in her own little hospice area. And then I sampled the males for their gonads.
But how representative is this behavior compared to opies in the wild? Maybe more representative than you'd think. This carnage was captured in the Bering Sea by ADF&G: