Elongated, narrow shells
distinguish mussels from other edible bivalves. Many varieties grow
worldwide, but blue and green mussels most commonly appear in local
markets. Identified by their inky, blue-black shells, blue mussels
grow wild or are farmed in cold Atlantic and Pacific waters, while
jade-color "greenshells" come from New Zealand. All varieties offer
a good source of protein, calcium, magnesium, and selenium
