Found along shore of Stillwater River
I believe these are Mytilis trossulus, or the Pacific Blue Mussel. This site doesn't have either name, so I wonder if it may be Mytilis edulis?
Seen on the sandy backshore at Stillwater Cove.
An invasive species. Mondego river near Porto da Raiva, Portugal.
Abundant in the soil, but possibly brought in or road building materials?
Bivalvia is a class of marine and freshwater molluscs with laterally compressed bodies enclosed by a shell in two hinged parts. Bivalves include clams, oysters, mussels, scallops, and numerous other families of shells. The majority are filter feeders and have no head or radula. The gills have evolved into ctenidia, specialised organs for feeding and breathing. Most bivalves bury themselves in sediment on the seabed, where they are safe from predation. Others lie on the sea...