Overview
Cisco, sometimes referred to as lake herring, is the most widespread of the cisco-type fishes in North America. The cisco, along with the bloater and other ciscoes, played critical roles in the ecology of the Great Lakes as prey food for top predator fish like lake trout, perch and burbot.
Scientific Name
Identification Numbers
Characteristics
Food
Cisco feed on a variety of zooplankton, including copepods and amphipods, and sometimes, they feed on other young fish.
Physical Characteristics
The maximum age for a cisco is 10 years. Adults average 10 to 18 inches in length. They are elongate and elliptical in shape from their side, showing more curvature on their ventral side than their dorsal side.
Cisco are silver in color, with pink and purple iridescence. Their dorsal side is a deep blue green and they have a white belly. Their fins are light in pigment, almost transparent, but the ends of their tail and dorsal fins are dark in color.
Life Cycle
Spawning occurs in fall and winter at depths of 1 to 140 meters (3 to 420 feet). Adults feed mostly in the pelagic, or open water, areas of the lake on a wide variety of zooplankton, like copepods and amphipods.
Cisco inhabit the full range of depths in the Great Lakes, depending on time of year, time of day and life stage. While the maximum depths they occupy range from 90 to 150 meters (270 to 450?feet), cisco also are found in shallower water from 1 to 3 meters (3 to 10 feet) during spawning, and they are found feeding in surface waters in winter and spring.
Habitat
Cisco inhabit the full range of depths in the lakes, but the maximum depths they have been found at range from 270 feet to 450?feet. They are found in shallower water of 3 to 10 feet during spawning.
Geography
Cisco are native to all of the Great Lakes and including Lake Nipigon in Ontario, Canada. They inhabit the full range of depths in the lakes, depending on time of year, time of day and life stage.