Coregonus kiyiKiyi

Ge­o­graphic Range

Kiyi are found only in the Great Lakes be­tween the United States and Canada. They are com­monly found in Lake Su­pe­rior but are rare in Lake Huron and Lake On­tario and en­dan­gered in Lake Michi­gan. None are found in Lake Erie. COSEWIC con­sid­ers this species to be ex­tir­pated in all Great Lakes ex­cept Lake Su­pe­rior. ("As­sess­ment and Up­date Sta­tus Re­port on the Lake On­tario Kiyi and Upper Great Lakes Kiyi", 2005; Eakins, 2011; Froese, et al., 2011)

Habi­tat

Found only in the Lau­rent­ian Great Lakes of North Amer­ica, kiyi re­quire a fresh­wa­ter cli­mate and re­side at depths of 35 to 200 m. Al­though they are oc­ca­sion­ally found in shal­lower wa­ters, kiyi pre­fer wa­ters of at least 108 m in depth. They are found in water of tem­per­a­tures rang­ing from 3.7 to 4.6˚C. Kiyi live in clear, dark water and have been col­lected over bot­toms of clay and mud sub­strate. ("As­sess­ment and Up­date Sta­tus Re­port on the Lake On­tario Kiyi and Upper Great Lakes Kiyi", 2005; Car­lan­der, 1969; Eakins, 2011; Froese, et al., 2011)

  • Range depth
    200 to 35 m
    656.17 to 114.83 ft

Phys­i­cal De­scrip­tion

Kiyi are long, thin, el­lip­ti­cally shaped, and lat­er­ally com­pressed fish. They are cov­ered in large sil­very scales. Al­though col­oration varies, they are gen­er­ally dark on the top, sil­very on the side, and white on the un­der­side. Pur­ple and pink iri­des­cence is no­tice­able. Kiyi av­er­age 25 cm in length and can range from 12 to 35 cm in length. The head com­prises roughly a quar­ter of the length. They have large eyes, and the lower jaw may pro­trude be­yond the upper jaw or be ter­mi­nal. Gill rak­ers are medium to long and num­ber from 40 to 45. The spine is com­prised of 55 to 58 ver­te­brae, and their lat­eral line has 71 to 91 scales. Kiyi have 9 to 11 dor­sal soft rays, 9 to 16 anal soft rays, 15 to 18 pec­toral soft rays, 11 to 12 pelvic soft rays, and a forked cau­dal fin. Kiyi weigh be­tween 0.4 and 0.16 kg. Kiyi are si­m­il­iar in ap­pear­ance to other species of white­fish, but are eas­ily dis­tin­guished by their large eyes and paired fins. (Froese, et al., 2011; Hubbs and La­gler, 2004; "Kiyi (Upper Great Lakes Pop­u­la­tion)", 2008; "Kiyi (Core­gonus kiyi)", 2009a)

There are two sub­species of kiyi, upper Great Lakes kiyi (Core­gonus kiyi kiyi), lo­cated in Lake Su­pe­rior, and Lake On­tario kiyi (Core­gonus kiyi), once found in Lake On­tario. Upper Great Lakes kiyi have fewer gill rak­ers, a longer head, and longer paired fins. In May 2005, Core­gonus kiyi was de­clared ex­tinct due to pre­da­tion, com­pe­ti­tion, and over har­vest­ing from com­mer­cial fish­ing. ("Kiyi (Upper Great Lakes Pop­u­la­tion)", 2008)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    0.04 to 0.16 kg
    0.09 to 0.35 lb
  • Range length
    12 to 35 cm
    4.72 to 13.78 in
  • Average length
    25 cm
    9.84 in

De­vel­op­ment

Lit­tle in­for­ma­tion is avail­able re­gard­ing the de­vel­op­ment of kiyi. How­ever, de­vel­op­ment is likely sim­i­lar to that of other mem­bers of the genus, such as lake white­fish. Fe­male lake white­fish gain weight faster and are heav­ier than males, though they are gen­er­ally the same length. Lake white­fish eggs in­cu­bate for 120 to 140 days and hatch in March or April. Hatch­lings reach a length of 13 mm by 3 weeks of age. Mor­tal­ity of lake white­fish fry is 87%. Growth is ini­tially rel­a­tively slow and in­creases from June to the end of July. In lab­o­ra­tory tests, lake white­fish eggs did not sur­vive at tem­per­a­tures below 0˚C or above 12˚C. Egg mor­tal­ity in­creased with in­creas­ing tem­per­a­ture. In­cu­ba­tion time de­creased with in­creas­ing tem­per­a­ture. (Car­lan­der, 1969)

Re­pro­duc­tion

Kiyi are lithopelagophils, mean­ing they spawn over open grav­elly areas. They prac­tice ex­ter­nal fer­til­iza­tion, and eggs are scat­tered across the sub­strate. Lit­tle in­for­ma­tion is oth­er­wise avail­able re­gard­ing the mat­ing sys­tems of kiyi, how­ever, they are likely sim­i­lar to that of other mem­bers of the genus. Lake white­fish males have pro­nounced breed­ing tu­ber­cles, and they pre­cede fe­males to spawn­ing areas. Spawn­ing is promis­cu­ous and most com­monly oc­curs at night. Eggs and sperm are re­leased near the sur­face of the water after a dis­play of up­ward move­ment. Fe­male lake white­fish re­lease eggs in small batches over a pe­riod of ten days. Eggs are de­scribed as semi buoy­ant, non-ad­he­sive, 2 to 3 mm in di­am­e­ter, and num­ber 53,000 per fluid quart. Nat­ural fer­til­iza­tion is about 80%. (Car­lan­der, 1969; Eakins, 2011)

Kiyi gen­er­ally spawn in the fall. In Lake Su­pe­rior, spawn­ing oc­curs from No­vem­ber to De­cem­ber at depths around 128 m. When kiyi pop­u­lated other lakes, spawn­ing was known to occur from Sep­tem­ber to Jan­u­ary at depths of 106 to 165 m de­pend­ing on the lake. They prac­tice ex­ter­nal fer­til­iza­tion, scat­ter­ing their eggs across a grav­elly sub­strate. At the time of spawn­ing fe­males are gen­er­ally heav­ier than males of the same length. Fe­males lse about 6.2 to 14.4 % (mean 11.8%) of their weight while males lose 0 to 7.4 % (mean 1.6%). Eggs hatch in 120 to 140 days. Kiyi reach ma­tu­rity at an age of 2 to 3 years, gen­er­ally at a length of at least 132 mm. ("As­sess­ment and Up­date Sta­tus Re­port on the Lake On­tario Kiyi and Upper Great Lakes Kiyi", 2005; Car­lan­der, 1969)

  • Breeding interval
    Kiyi breed once a year.
  • Breeding season
    Spawning occurs from November to December in Lake Superior.
  • Range time to hatching
    120 to 140 days
  • Range age at sexual or reproductive maturity (female)
    2 to 3 years
  • Range age at sexual or reproductive maturity (male)
    2 to 3 years

Kiyi do not guard their eggs after spawn­ing, and they are not known to pro­vide parental care after their off­spring hatch. (Car­lan­der, 1969; Eakins, 2011)

  • Parental Investment
  • pre-fertilization
    • provisioning
    • protecting
      • female

Lifes­pan/Longevity

The lifes­pan of kiyi is 7 to 8 years for males and 9 to 10 years for fe­males. Fe­males have been known to live more than 10 years. ("As­sess­ment and Up­date Sta­tus Re­port on the Lake On­tario Kiyi and Upper Great Lakes Kiyi", 2005; Eakins, 2011)

  • Typical lifespan
    Status: wild
    male 7; female 9 to male 8; female 10 years

Be­hav­ior

Lit­tle in­for­ma­tion is avail­able re­gard­ing be­hav­ior of kiyi. Lake white­fish, also deep cold water fish in the genus, are typ­i­cally seden­tary and spend most of their time in loosely ag­gre­gated schools. (Dewey, 2008; Tomel­leri and Eberle, 1990)

Home Range

The move­ment and home range of kiyi have not been well stud­ied. Lake white­fish, how­ever, have been tagged and their move­ments mon­i­tored. In Lake Erie, in­di­vid­ual lake white­fish mi­grate be­tween deep water and spawn­ing grounds at a dis­tance of 280 km. In Lake Michi­gan, some in­di­vid­u­als trav­eled far­ther than 40 km with a max­i­mum dis­tance of 115 km in a year. (Car­lan­der, 1969)

Com­mu­ni­ca­tion and Per­cep­tion

Kiyi have large eyes that are uniquely adapted for their deep­wa­ter habi­tat. Be­cause of their lat­eral line, they can also sense move­ment in the sur­round­ing water. Com­mu­ni­ca­tion among near rel­a­tives lake white­fish is tac­tile. ("As­sess­ment and Up­date Sta­tus Re­port on the Lake On­tario Kiyi and Upper Great Lakes Kiyi", 2005; Dewey, 2008)

Food Habits

Kiyi pre­dom­i­nantly prey on small fresh­wa­ter shrimps and may also prey on opos­sum shrimp, am­phipods, mayfly nymphs, mol­lusks, zoo­plank­ton, ben­thos, and chi­rono­mids. More specif­i­cally, prey in­clude Pon­to­por­eia, Mysis in­clud­ing Mysis re­licta, and Di­por­eia hoyi. ("As­sess­ment and Up­date Sta­tus Re­port on the Lake On­tario Kiyi and Upper Great Lakes Kiyi", 2005; "Lake Su­pe­rior Food Web", 2009; Car­lan­der, 1969; Hubbs and La­gler, 2004)

  • Animal Foods
  • mollusks
  • aquatic crustaceans
  • zooplankton

Pre­da­tion

Kiyi are preyed upon by bur­bots and lake trout, as well as hu­mans. Other po­ten­tial preda­tors in­clude sea lam­prey, rain­bow smelt, and alewife. ("As­sess­ment and Up­date Sta­tus Re­port on the Lake On­tario Kiyi and Upper Great Lakes Kiyi", 2005)

Ecosys­tem Roles

Kiyi prey upon a va­ri­ety of zoo­plank­ton and macroin­ver­te­brates and also serve as prey for pis­ci­vores. ("Lake Su­pe­rior Food Web", 2009)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Kiyi were once very im­por­tant com­mer­cial fish in the Great Lakes and were heav­ily fished. Deep-wa­ter cisco fish­ing, com­monly re­ferred to as chub fish­ing, is no longer prac­ticed in the Amer­i­can por­tion of Lake Su­pe­rior but still oc­curs in Cana­dian wa­ters. Quo­tas re­main well below the mean ex­ploitable bio­mass and are only roughly one-tenth the es­ti­mated pre­sent pop­u­la­tion size. White­fishes in gen­eral make up the largest com­mer­cial fish­ery in the Great Lakes. How­ever, kiyi have low mar­ketabil­ity and the de­mand is gen­er­ally low. ("As­sess­ment and Up­date Sta­tus Re­port on the Lake On­tario Kiyi and Upper Great Lakes Kiyi", 2005; "Core­gonus kiyi — kiyi", 2000)

  • Positive Impacts
  • food

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no known ad­verse ef­fects of kiyi on hu­mans. (Froese, et al., 2011)

Con­ser­va­tion Sta­tus

Kiyi are listed as vul­ner­a­ble by the IUCN and are con­sid­ered of spe­cial con­cern by the US Fish and Wildlife ser­vice, the states of Michi­gan, In­di­ana, Min­nesota, Wis­con­sin, New York, and the On­tario Min­istry of Nat­ural Re­sources. ("As­sess­ment and Up­date Sta­tus Re­port on the Lake On­tario Kiyi and Upper Great Lakes Kiyi", 2005; "Core­gonus kiyi — kiyi", 2000; "Kiyi (Core­gonus kiyi)", 2009a; "Kiyi (Core­gonus kiyi)", 2009b)

Over­fish­ing con­tributed greatly to the ex­tir­pa­tion of kiyi in lakes Huron, Michi­gan and On­tario. Al­though they are not cur­rently a tar­geted species, kiyi are oc­ca­sion­ally taken as by-catch for other com­mer­cial fish­eries. Other threats to this species in­clude loss of cold deep-wa­ter habi­tat as well as habi­tat degra­da­tion due to con­t­a­m­i­nants and sed­i­men­ta­tion. This species is par­tic­u­larly vul­ner­a­ble to these processes as they are en­demic to a sin­gle lake. Com­pe­ti­tion with and pre­da­tion by ex­otic species such as alewife, smelt, pa­cific salmon, and sea lam­prey are the great­est threat to ex­ist­ing pop­u­la­tions of kiyi. ("As­sess­ment and Up­date Sta­tus Re­port on the Lake On­tario Kiyi and Upper Great Lakes Kiyi", 2005; "Core­gonus kiyi — kiyi", 2000; "Kiyi (Core­gonus kiyi)", 2009a; "Kiyi (Core­gonus kiyi)", 2009b)

Con­ser­va­tion ef­forts should focus on the con­trol of ex­otic species in Lake Su­pe­rior, and reg­u­la­tion of com­mer­cial fish­eries that neg­a­tively af­fect kiyi. Ad­di­tion­ally, more in­for­ma­tion is re­quired re­gard­ing the abun­dance of this species. Reestab­lish­ment in Lake Huron and Lake Michi­gan may be pos­si­ble using pop­u­la­tions from Lake Su­pe­rior, al­though this has not yet oc­curred. ("As­sess­ment and Up­date Sta­tus Re­port on the Lake On­tario Kiyi and Upper Great Lakes Kiyi", 2005; "Core­gonus kiyi — kiyi", 2000; "Kiyi (Core­gonus kiyi)", 2009a; "Kiyi (Core­gonus kiyi)", 2009b)

Other Com­ments

In 1927, kiyi made up roughly 52.8% of all cis­coes caught in ex­per­i­men­tal gill nets in Lake On­tario. By 1942 they com­prised only 0.01%, and only 1 in­di­vid­ual was caught in 1964. This was the last recorded pres­ence of kiyi in Lake On­tario. ("As­sess­ment and Up­date Sta­tus Re­port on the Lake On­tario Kiyi and Upper Great Lakes Kiyi", 2005)

Con­trib­u­tors

Brian Beall (au­thor), Min­nesota State Uni­ver­sity, Mankato, Robert Sorensen (ed­i­tor), Min­nesota State Uni­ver­sity, Mankato, Gail Mc­Cormick (ed­i­tor), An­i­mal Di­ver­sity Web Staff, Cather­ine Kent (ed­i­tor), Spe­cial Pro­jects.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

external fertilization

fertilization takes place outside the female's body

fertilization

union of egg and spermatozoan

filter-feeding

a method of feeding where small food particles are filtered from the surrounding water by various mechanisms. Used mainly by aquatic invertebrates, especially plankton, but also by baleen whales.

food

A substance that provides both nutrients and energy to a living thing.

freshwater

mainly lives in water that is not salty.

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

pelagic

An aquatic biome consisting of the open ocean, far from land, does not include sea bottom (benthic zone).

planktivore

an animal that mainly eats plankton

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate

visual

uses sight to communicate

zooplankton

animal constituent of plankton; mainly small crustaceans and fish larvae. (Compare to phytoplankton.)

Ref­er­ences

Com­mit­tee on the Sta­tus of En­dan­gered Wildlife in Canada. As­sess­ment and Up­date Sta­tus Re­port on the Lake On­tario Kiyi and Upper Great Lakes Kiyi. Ot­tawa: Her Majesty the Queen in Right of Canada. 2005. Ac­cessed April 22, 2011 at http://​dsp-psd.​pwgsc.​gc.​ca/​Collection/​CW69-14-431-2005E.​pdf.

USGS Great Lakes Sci­ence Cen­ter. 2000. "Core­gonus kiyi — kiyi" (On-line pdf). GLSC Fact Sheet 2000-2. Ac­cessed July 09, 2011 at http://​www.​glsc.​usgs.​gov/_​files/​factsheets/​2000-2%20Coregonus%20Kiyi.​pdf.

Michi­gan Nat­ural Fea­tures In­ven­tory. 2007. "Core­gonus kiyi" (On-line). Rare Species Ex­plorer. Ac­cessed April 22, 2011 at http://​web4.​msue.​msu.​edu/​mnfi/​explorer/​species.​cfm?​id=11283.

Wis­con­sin De­part­ment of Nat­ural Re­sources. 2009. "Kiyi (Core­gonus kiyi)" (On-line). En­dan­gered Re­sources Pro­gram Species In­for­ma­tion. Ac­cessed April 22, 2011 at http://​dnr.​wi.​gov/​org/​land/​er/​biodiversity/​index.​asp?​mode=info&​Grp=13&​SpecCode=AFCHA01070.

Wis­con­sin De­part­ment of Nat­ural Re­sources. 2009. "Kiyi (Core­gonus kiyi)" (On-line pdf). Wis­con­sin’s Strat­egy for Wildlife Species of Great­est Con­ser­va­tion Need. Ac­cessed July 09, 2011 at http://​www.​dnr.​state.​wi.​us/​org/​land/​er/​wwap/​plan/​pdfs/​Fish_​Kiyi.​pdf.

Royal On­tario Mu­seum. 2008. "Kiyi (Upper Great Lakes Pop­u­la­tion)" (On-line). On­tario's Species at Risk. Ac­cessed July 09, 2011 at http://​www.​rom.​on.​ca/​ontario/​risk.​php?​doc_​type=fact&​id=65&​lang=en.

NOAA. Lake Su­pe­rior Food Web. Ann Arbor, MI: Great Lakes En­vi­ron­men­tal Re­search Lab­o­ra­tory. 2009. Ac­cessed April 22, 2011 at http://​www.​glerl.​noaa.​gov/​pubs/​brochures/​foodweb/​LSfoodweb.​pdf.

Car­lan­der, K. 1969. Hand­book of Fresh­wa­ter Fish­ery Bi­ol­ogy. Ames, IA: The Iowa State Uni­ver­sity Press.

Dewey, T. 2008. "Core­gonus clu­peaformis" (On-line). An­i­mal Di­ver­sity Web. Ac­cessed May 02, 2011 at http://​animaldiversity.​ummz.​umich.​edu/​site/​accounts/​information/​Coregonus_​clupeaformis.​html.

Eakins, R. 2011. "Kiyi" (On-line). On­tario Fresh­wa­ter Fishes Life His­tory Data­base. Ver­sion 3.95.. Ac­cessed July 09, 2011 at http://​ecometrix.​ca/​fishdb/​fish_​detail.​php?​FID=94.

Froese, R., S. Ku­os­ma­nen-Pos­tila, R. Reyes, A. Tor­res. 2011. "Fish­Base" (On-line). Ac­cessed April 03, 2011 at http://​www.​fishbase.​org/​summary/​SpeciesSummary.​php?​id=2672.

Hubbs, C., K. La­gler. 2004. Fishes of the Great Lakes Re­gion. Ann Arbor, MI: The Uni­ver­sity of Michi­gan Press.

Tomel­leri, J., M. Eberle. 1990. Fishes of the Cen­tral United States. Lawrence, Kansas: Uni­ver­sity Press of Kansas.