Rockefeller 3-19

[cajun bill]

If you put the crabs in the water before the water gets hot, they will not eject their claws and legs like they do when you throw cold crabs in boiling water. While they will still lose some, almost all claws and legs will stay on the shell making it easier to get at the meat when you peel them.

Of course, this only works on the first batch because after that, the water is hot. I read about this years ago and it is a trick restaurants use to make their crabs more attractive to the consumer. Don't know about taking the shell off along with the "gills". Never saw that done and like you said, you lose the fat.