There are mussels that start out and remain green (New Zealand spp., if I recollect), and they are DAMN TASTY! I LOVE mussels! As a matter of fact, when the beau took me out to a great restaurant (sweetheart did it two nights in a row) I had a chance to have the mussels as a first course on the second night and OHMYGOD, they were so good! They also make excellent bait for bass (calico, striped, sand), and maybe for halibut, though I've never been so lucky.