Cisco are coldwater fish having dark blue to pale olive backs and silvery sides. All their fins are basically clear, although the anal and pelvic fins are milky on adults. This fish has a protruding lower jaw forked tail, and an adipose fin.
Cisco are widely distributed in lakes cross New York.
It is present in Lakes Erie and Ontario, tributaries of the St. Lawrence River, Otsego Lake, and in various lakes in the Adirondacks including Lake Champlain. Spawning occurs in late fall, when large spawning groups congregate. Males move to spawning areas before females. In large lakes, spawning may occur in shallow water or in deep water. Cisco are a schooling fish, usually frequenting deep water.