Here's a video of my Takifugu ocellatus going nuts about it and ended up with a big belly bump after the scrumptious meal:
http://www.youtube.com/watch?v=01fgR2BsQLo
I cracked open about 1/3 of the crab, washed all the innards out as they just cloud the water like crazy, and threw it into the tank.
Tried it on my GSP as well but he was more confused about it. I'll experiment a little more....

