Standing Out in Mytilus trossulus

Patches of shiny black or blue-black Mytilus trossulus* show up every once in a while. The patches don’t last long. I’ve never seen an established bed. Their vulnerability to predatory starfish and snails may partially explain their failure to persist.


Almost every patch has one or more orangish-brown standouts.

*It’s not a slam dunk these are Mytilus trossulus. Three similar mussels occur on our shores, and they hybridize. Blue or bay mussels are the most frequently used common names.

Blending In – or Standing Out?