Length to 30 inches and weight to 12 pounds, more commonly to 20 inches and 5 or 6 pounds. Females are larger than males.
3.85 lbs; Tom Magnuson; Columbia River, Clark County; June 21, 2005
The back is metallic-blue to greenish, shading through white to silvery on the belly. A row or rows of dark spots decreases in size toward the tail. These spots are not always visible, but show up when the fish are scaled. A very distinctive characteristic is the saw-like serrated edge along the midline of the belly.
Like salmon and steelhead, shad are anadromous. They enter freshwater rivers in the spring to spawn. Unlike Pacific salmon, they do not necessarily die after spawning. Many shad continue to spawn annually.
For more information on American shad see: http://wdfw.wa.gov/fishing/shad/