One for me I think as I was there on the weekend ;-)
The edible crab, also called the brown crab is the most commonly eaten crab in the uk. There is a minimum keeping size of 12cm though this only strictly applies if you are selling them. The females carry eggs and therefore should be thrown back for the sake of conservation of food stocks.
The shore crab, also called the green crab is also edible and is a highly prized in venice.
Spider crabs, the ones with the spiky shells can also be eaten... the meat is sweeter and more commonly eaten in spain than the uk.
Recent experience suggests that it may be to with the amount of meat in the body
That stuff in the shell is edible, just remember to remove the dead mens fingers (see a post further back about this). Most people expect 'meat' in the shell as that how it is normaly served.... where infact the shell is normaly scraped clean and mixed with the white meat of the claws and legs before being put back in the shell and served..... hence people expect nice white crab meat in the shell.... In the brown edible crab, for example, after the dead mens fingers, stomach etc have been removed you are left with a rich creamy brown meat...... lovely
Hope this helps and I hope you enjoyed your 'Recent Experience'
Ed