Alosa

Alosa is a genus of fish belonging to the herring family (Clupeidae), commonly known as shads. These saltwater fish are characterized by their deep bodies and a distinctive notch in their upper jaw where the lower jaw fits. While young shads have teeth, adults are toothless.12

The most well-known species is the American shad (Alosa sapidissima), which migrates up rivers to spawn. It was introduced to the Pacific Ocean and now ranges along the west coast of North America. Other species include the European Allis shad (A. alosa) and the smaller twaite shad (A. finta). Shad flesh is considered good to eat, though bony, and their roe is a delicacy.1