Raw shrimp: it will turn pink and become firm
Live oysters, clams, and mussels: the shells will open when they are done
Shucked oysters, clams, and mussels: they will become plump and opaque. The edges of the oysters will start to curl
Scallops: they will turn white or opaque and become firm to the touch
Crab and lobster: the shells will turn bright red and the meat will become white or opaque.
