Animal Diversity Web

Ge­o­graphic Range

Lake chub (Coue­sius plumbeus) have the widest north­ern dis­tri­b­u­tion of any North Amer­i­can min­now. They can be found widely through­out Canada. In the north-tem­per­ate lat­i­tudes of the United States, they in­habit the upper reaches of the Mis­souri River Basin, the Great Lakes re­gion, and the north­ern At­lantic slope drainages, with pres­ence in east­ern Iowa, north­ern Ne­braska, and north-cen­tral Col­orado as a glacial relict. (Becker, 1983; Beste­gen, et al., 1991; Stasiak, 2006; Wells, 1980)

• Biogeographic Regions
• nearctic
  • native

Habi­tat

Lake chub pre­fer cool, shal­low wa­ters, how­ever, they can thrive in a wide va­ri­ety of en­vi­ron­ments and are found in both streams and lakes of all sizes through­out their range. They more com­monly in­habit lakes in the south­ern por­tion of their range, and rivers in the north­ern por­tion. In lakes, they are often found near shores over sandy bot­toms with oc­ca­sional large-sized boul­ders. In streams they are more com­monly found at river-mouths, at depths of about 1 meter or less. (Becker, 1983)

• Habitat Regions
• temperate
• freshwater

• Aquatic Biomes
• lakes and ponds
• rivers and streams

Phys­i­cal De­scrip­tion

Lake chub have an elon­gated body with a nearly round cross sec­tion. Their dor­sal fin orig­i­nates over the pelvic fin and the lat­eral line is com­plete. Their back and upper sides are lead gray. They are sil­ver to sil­ver-white below the lat­eral line, with the oc­ca­sional dark­ened scales on their sides, giv­ing them a dis­tinct speck­led ap­pear­ance, which is easy to iden­tify in the field. Their snout is bluntly rounded and slightly over­hangs their mouth. Their mouth is large, al­most reach­ing the an­te­rior mar­gin of their eyes, with a long promi­nent bar­bell in each cor­ner. They also have hooked pha­ryn­geal teeth and short gill­rak­ers. (Becker, 1983; Brown, et al., 1970)

Lake chub ex­hibit sex­ual di­mor­phism. Males gen­er­ally have larger pec­toral fins, which are long and sub­cir­cu­lar with a gap be­tween the end of the pec­toral fin and the ori­gin of the pelvic fin that is about half the length of the pec­toral fin. Dur­ing breed­ing, males show a faint rosy color at the cor­ner of the mouth, on the upper lip, and above the lip groove. In ad­di­tion, the upper angle of op­er­cle ex­tends into the op­er­cu­lar cav­ity. Like­wise, the base of the pelvic fin dis­plays a rosy spot, the side of the body above the paired and anal fins has a 3 to 6 mm wide faint rosy stripe, and there is a dis­tinct black lat­eral stripe dur­ing courtship. Fe­males are gen­er­ally larger and have short, ovate pec­toral fins with a gap of about three-fourths the length of the pec­toral fin be­tween the end of the pec­toral fin and the ori­gin of the pelvic fin. Dur­ing breed­ing, fe­males dis­play a rosy color about the base of the pec­toral fin and have a sil­very peri­toneum. In both sexes, tu­ber­cles ap­pear dur­ing breed­ing, with males dis­play­ing fine tu­ber­cles on the top of the head, op­er­cles, cheeks, edges of scales of the back, scales of the sides to the lat­eral line, breast, cau­dal pe­dun­cle, and the rays of the pec­toral and pelvic fins. Fe­males ap­pear sim­i­lar; how­ever, the male is less heav­ily tu­ber­cu­late, only dis­play­ing tu­ber­cles on the an­te­rior-most rays of the paired fins. (Becker, 1983; Brown, et al., 1970)

• Other Physical Features
• bilateral symmetry

• Sexual Dimorphism
• female larger

• Average length

  127 mm

  5.00 in

De­vel­op­ment

Lake chub eggs are de­m­er­sal and non-ad­he­sive, with a dark golden yolk. They have a nar­row periv­itelline space that is only vis­i­ble on one side. These eggs range in di­am­e­ter from 1.8 to 2.4 mm after fer­til­iza­tion. The lar­vae have 26 to 28 pre­anal my­omeres and a row of melanophores an­te­ri­orly de­scend­ing across the lat­eral sur­face of the breast. Newly hatched lar­vae range in length from 5.8 to 6.4 mm, and have small pec­toral buds, formed func­tional mouth parts, an in­flated pos­te­rior gas blad­der cham­ber, formed an­te­rior cham­ber, os­si­fied first cau­dal fin rays, formed first dor­sal fin rays, anal fin rays, and pelvic fin rays. There is rapid change in lar­vae body pro­por­tions, this growth is rapid until the lar­vae reaches about 9 mm and the rate of growth lessens. Lake chub gen­er­ally reach mat­u­ra­tion at age three and very few live be­yond the age of four, al­though lake chub older than four have been found. (Becker, 1983; Fuiman and Baker, 1981)

Re­pro­duc­tion

Dur­ing spawn­ing, male lake chub ac­tively pur­sue fe­males to in­duce mat­ing. When a fe­male is near a spawn­ing-ready male or males, the males charge her from be­neath and tena­ciously nose her vent re­gion, forc­ing the fe­male up­ward, some­times re­sult­ing in her break­ing the water sur­face. The male then swims next to the fe­male's op­er­cu­lum, and if mul­ti­ple males are still pre­sent, they swim side by side to com­pete for a po­si­tion next to the fe­male. Dur­ing this courtship process, the male's lat­eral body stripe be­comes darker and more dis­tinct, and their mouth opens and closes rapidly. This process con­tin­ues until the fe­male swims to a rock, when the re­main­ing male forces him­self against her, vi­brat­ing vig­or­ously until the eggs are ex­truded from her, re­sult­ing in im­me­di­ate fer­til­iza­tion by the male. (Brown, et al., 1970)

• Mating System
• polyandrous

Lake chub spawn­ing oc­curs in the spring at lower lat­i­tudes and later in the sum­mer in higher lat­i­tudes. Lake chub have the abil­ity to spawn in a di­verse range of habi­tats and sub­strates, in­clud­ing river shal­lows, along rocky shores, in lake shoals, and on silt, leaves, gravel, or rocks. How­ever, they most fre­quently enter creeks and streams or travel along lakeshores to spawn, al­though river-breed­ing chub do not in­ter­min­gle with lake-breed­ing chub. Spawn­ing mi­gra­tions can range from less than 0.8 km (0.5 miles) to up to 1.6 km (1 mi). Tem­per­a­ture is a major fac­tor in re­gards to sperm de­vel­op­ment, as low tem­per­a­tures (5-12°C, 41-53.6°F) dur­ing the win­ter be­fore spawn­ing are nec­es­sary for nor­mal go­nadal pro­lif­er­a­tion and the for­ma­tion of the pri­mary sper­ma­to­cytes. Tem­per­a­tures higher than these can re­sult in pre­ma­ture sperm pro­duc­tion, or even ter­mi­na­tion. At the other end of the process, if tem­per­a­tures are too high after spawn­ing the dis­ap­pear­ance of sper­matids and sperm can occur, as well as a rapid re­gres­sion of the testis. (Becker, 1983; Brown, et al., 1970; Stasiak, 2006)

• Key Reproductive Features
• sexual
• fertilization
  • external

• Breeding interval

  Breeding generally occurs several times per minute, however, each act of spawning only lasts about one second.

• Breeding season

  Depending on the region, lake chub spawning occurs during the spring or summer months.

• Range number of offspring

  800 to 2400

• Range time to hatching

  8 to 10 days

• Average age at sexual or reproductive maturity (female)

  Age class III years

• Average age at sexual or reproductive maturity (male)

  Age class III years

There has been no ev­i­dence of parental care of eggs or ju­ve­niles by lake chub, nor has any nest con­struc­tion been doc­u­mented. (Becker, 1983)

• Parental Investment
• no parental involvement

Lifes­pan/Longevity

Very few lake chub live past the age of four years. How­ever, their av­er­age lifes­pan is about five years and they have been known to live up to seven years. Fe­male lake chub are thought to grow faster and live longer than males. (Coad, et al., 1995; Scott and Cross­man, 1973)

• Range lifespan
  Status: wild

  7 (high) years

• Average lifespan
  Status: wild

  4 years

Be­hav­ior

Lake chub are a so­cial species that ag­gre­gate in large schools and mi­grate to spawn­ing grounds to­gether in the spring, but shift to deeper wa­ters in the sum­mer for cooler tem­per­a­tures. This species is con­sid­ered di­ur­nal. How­ever, dur­ing times of mi­gra­tion, when di­ur­nal preda­tors are more aware of their pres­ence, lake chub may be­come ac­tive dur­ing the night, pre­sum­ably to avoid pre­da­tion. This change shows pos­si­ble flex­i­bil­ity in their ac­tiv­ity pat­terns. (Reebs, 2001; Smith, 2010)

• Key Behaviors
• natatorial
• diurnal
• motile
• social

Home Range

These fish mi­grate for spawn­ing each year. These mi­gra­tions can range from less than 0.8 km (0.5 miles) to up to 1.6 km (1 mi). (Becker, 1983; Brown, et al., 1970; Stasiak, 2006)

Com­mu­ni­ca­tion and Per­cep­tion

Lake chub are thought to lack ex­ter­nal taste buds, there­fore per­cep­tion is achieved through the use of vi­sion. (Davis and Miller, 1967)

• Perception Channels
• visual
• tactile
• chemical

Food Habits

Young lake chub con­sume small aquatic crus­taceans such as clado­cer­ans and cope­pods. These crus­taceans re­main in their diet as they grow older; how­ever, older lake chub pri­mar­ily con­sume in­sects, al­though some in­di­vid­u­als also con­sume small amounts of snails and fish eggs. Be­cause lake chub have an al­most com­plete lack of ex­ter­nal taste buds, they are most likely oblig­a­tory sight feed­ers. (Becker, 1983; Davis and Miller, 1967)

• Primary Diet
• carnivore
  • insectivore
  • eats non-insect arthropods

• Animal Foods
• fish
• eggs
• insects
• aquatic crustaceans

Pre­da­tion

Known preda­tors of lake chub in­clude both preda­tory fishes and birds such as lake trout, bur­bot, walleyes, and north­ern pike, as well as mer­gansers, king­fish­ers, and com­mon loons. They also have sev­eral mam­malian preda­tors such as minks, martens, ot­ters, fish­ers, and rac­coons. To avoid such preda­tors in areas where they are es­pe­cially sus­cep­ti­ble to pre­da­tion, such as streams dur­ing spawn­ing, these di­ur­nal fish have been known to be more ac­tive dur­ing the night. Lake chub lar­vae and ju­ve­niles also have their own preda­tors, in­clud­ing div­ing bee­tles, giant water bugs, and drag­on­flies. (Coad, et al., 1995; Reebs, 2001; Scott and Cross­man, 1973; Stasiak, 2006)

• Known Predators

  • lake trout (Salvelinus namaycush)
  • burbot (Lota lota)
  • walleye (Sander vitreus)
  • northern pike (Esox lucius)
  • mergansers (Merginae)
  • kingfishers (Alcedinidae)
  • common loons (Gavia immer)
  • minks (Neovison vison)
  • martens (Martes)
  • otters (Lutrinae)
  • fishers (Martes pennanti)
  • raccoons (Procyon lotor)
  • diving beetles (Dytiscidae)
  • giant water bugs (Belostomatidae)
  • dragonflies (Odonata)

Ecosys­tem Roles

Lake chub have often been found as hosts to many types of small par­a­sites in­clud­ing the lar­val form of trema­todes (Diplosto­mu­lum and Posthodiplosto­mum min­i­mum), the adult form of ne­ma­todes (Rhab­do­chona), acan­tho­cepha­lans (Echi­norhynchus salmo­nis), Pro­to­zoa, ces­todes, glochidia, and crus­taceans (Er­gasilus caeruleus). In many cases, lake chub ac­tu­ally act as an in­ter­me­di­ate host, with the final de­vel­op­ment phase tak­ing place in birds and other fishes. (Scott and Cross­man, 1973)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Lake chub have been ben­e­fi­cial to hu­mans for food both di­rectly and in­di­rectly. They are di­rectly ben­e­fi­cial as com­monly used live bait for early spring fish­ing, es­pe­cially in Canada. In ad­di­tion, smaller lake chub are often caught and eaten under the mis­taken im­pres­sion that they are smelt. (Coad, et al., 1995; Scott and Cross­man, 1973)

• Positive Impacts
• food

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

Brook trout an­glers fre­quently com­plain that lake chub in­ter­fere with their an­gling, as they often catch lake chub in­stead of brook trout. (Becker, 1983)

Con­ser­va­tion Sta­tus

Ac­cord­ing to the IUCN Red List, lake chub are a species of least con­cern due to the large ex­tent of their oc­cur­rence, the large num­ber of sub­pop­u­la­tions, their large pop­u­la­tion size, their ap­par­ently sta­ble pop­u­la­tion trends, and their lack of major threats. (Na­ture­Serve, 2013)

• IUCN Red List

  Least Concern

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Con­trib­u­tors

An­nalise Po­volo (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor, Lau­ren Sal­lan (ed­i­tor), Uni­ver­sity of Michi­gan-Ann Arbor, Jeff Scha­ef­fer (ed­i­tor), Uni­ver­sity of Michi­gan-Ann Arbor, Leila Si­cil­iano Mar­tina (ed­i­tor), An­i­mal Di­ver­sity Web Staff.

Ref­er­ences

Becker, G. 1983. Fishes of Wis­con­sin. Madi­son, WI: Uni­ver­sity of Wis­con­sin Press.

Beste­gen, K., K. Fausch, S. Riley. 1991. Re­dis­cov­ery of a relict south­ern pop­u­la­tion of Lake Chub, Coue­sius plumbeus, in Col­orado. The South­west­ern Nat­u­ral­ist, 31/1: 125-127.

Brown, J., U. Ham­mer, G. Koshin­sky. 1970. Breed­ing bi­ol­ogy of the lake chub, Coue­sius plumbeus, at Lac la Ronge, Saskatchewan. Jour­nal of the Fish­eries Board of Canada, 27/6: 1005-1015.

Coad, B., H. Waszczuk, I. Labig­nan. 1995. En­cy­clo­pe­dia of Cana­dian Fishes. Wa­ter­down, On­tario: Cana­dian Mu­seum of Na­ture and Cana­dian Sport­fish­ing Pro­duc­tions Inc.

Davis, B., R. Miller. 1967. Brain pat­terns in min­nows of the genus Hy­bop­sis in re­la­tion to feed­ing habits and habi­tat. Copeia, 1: 1-39.

Fuiman, L., J. Baker. 1981. Lar­val stages of the lake chub, Coue­sius plumbeus. Cana­dian Jour­nal of Zo­ol­ogy, 59/2: 218-224.

Na­ture­Serve, 2013. "IUCN Redlist of Threat­ened Species" (On-line). Coue­sius plumbeus. Ac­cessed July 21, 2014 at http://​www.​iucnredlist.​org/​details/​202072/​0.

Reebs, S. 2001. Fish Be­hav­ior in the Aquar­ium and in the Wild. United States of Amer­ica: Cor­nell Uni­ver­sity Press.

Scott, W., E. Cross­man. 1973. Lake chub: Coue­sius plumbeus (agas­siz). Pp. 401-406 in Fresh­wa­ter Fishes of Canada, Vol. 184, 1 Edi­tion. Canada: The Bryant Press Lim­ited.

Smith, G. 2010. Guide to Great Lakes Fishes. United States of Amer­ica: The Uni­ver­sity of Michi­gan Press.

Stasiak, R. 2006. "USDA For­est Ser­vice, Rocky Moun­tain Re­gion" (On-line). Lake Chub (Coue­sius plumbeus): A Tech­ni­cal Con­ser­va­tion As­sess­ment. Ac­cessed De­cem­ber 03, 2013 at http://​www.​fs.​fed.​us/​r2/​projects/​scp/​assessments/​lakechub.​pdf.

Wells, A. 1980. Coue­sius plumbeus (Agas­siz), Lake Chub. Pp. 854 in D Lee, ed. Atlas of North Amer­i­can Fresh­wa­ter Fishes, Vol. 1980, 12 Edi­tion. Raleigh, North Car­olina: North Car­olina State Mu­seum of Nat­ural His­tory.