Coregonus kiyi (Koelz, 1921)
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Basis for Listing
The Kiyi (Coregonus kiyi) is a deep-water cisco native to Lakes Ontario, Huron, Michigan, and Superior. It is now believed extirpated from Lakes Huron and Ontario and is endangered in Lake Michigan. Negative interactions with Alewives (Alosa pseudoharengus), a non-native species, are suspected in the decline of the Lake Michigan population, as Alewives are abundant at the same depths as Kiyi. Lake Superior and Minnesota represent the center of abundance for this species in North America (Lee et al. 1980; Becker 1983). For this reason, the Kiyi was listed as a special concern species in Minnesota in 1996.
The Kiyi has an elongated body that is laterally compressed, with an average total length of 25.9 cm (10.2 in.). Females are generally larger than males. Their lower jaw typically projects beyond the upper, usually with a prominent symphyseal knob. It has large, silvery scales, with pink or purple iridescence.
The Kiyi is very similar in appearance to the Cisco (C. artedi), Bloater (C. hoyi), and Shortjaw Cisco (C. zenithicus) (Lyons et al 2012). Kiyi differs from other ciscoes found in Minnesota by having long pelvic fins, large eyes, and a body shape that is oval in cross-section.
Kiyi are found in deep, clear, cold, open waters of large lakes. In Lake Superior, they have been found to be absent at depths of less than 37 m (121 ft.) and increasingly abundant down to 183 m (600 ft.) deep (Becker 1983).
Biology / Life History
The Kiyi spawns in the fall or early winter at depths of approximately 91-168 m (300-550 ft.) (Scott and Crossman 1973). Age at maturity is believed to be 2-3 years. Little is known about its feeding habits; however, analyses of gut contents have shown freshwater shrimp and amphipods as important food items (Becker 1983). The Kiyi is a likely prey species of Lake Trout (Salvelinus namaycush) and Burbot (Lota lota).
Conservation / Management
Threats to the Kiyi throughout the Great Lakes have included excessive commercial harvest; habitat degradation from sedimentation, contaminants, and disposal of dredged materials; and competition and predation from introduced non-native species (such as Alewife and Rainbow Smelt (Osmerus mordax)). In Lake Superior, no commercial fishery exists for the species, and significant competitors, such as Alewives, are presently uncommon.
Conservation Efforts in Minnesota
The Minnesota DNR Division of Fisheries records any occurrences of Kiyi found while conducting their annual fish surveys. As the Kiyi’s range wide distribution is currently limited to Lake Superior, population monitoring to detect changes in abundance is warranted and necessary for the long-term conservation of the species. Preventing further introductions of non-indigenous species and continuing current efforts to suppress existing exotic species populations in Lake Superior should also be high priorities. Additional research into the Kiyi's life history and refining genetic analysis methods for all cisco species would aid in the conservation of this rare fish species.