fascinating yet horrifying web site. Apparently, crabs are ultra-communicative family men, finding burrows to protect their females and their eggs, while lobsters are immortal, loner cannibals. Seriously! Lobsters eat each other in captivity, and they cannot die of old age. Instead, they actually grow stronger and more fertile as they get older.
No wonder lobster is so expensive -- eating lobster is like being the Highlander. And that is why Red Lobster is a place you take your girlfriend for dinner, while Red Crab sounds like something your girlfriend will dump you for giving her. (Thanks to Mojo for the screenshot.)