Cisco (fish)

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Ciscoes
Cisco.jpg
Coregonus artedi
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Coregonus (in part)

The ciscoes (or ciscos) are salmonid fish that differ from other members of the genus Coregonus in having upper and lower jaws of approximately equal length and high gill raker counts. These species have been the focus of much study recently, as researchers have sought to determine the relationships among species that appear to have evolved very recently. The term cisco is also specifically used of the North American species Coregonus artedi , also known as lake herring.

Contents

In previous taxonomic classifications, the ciscoes have been identified as a subgenus Leucichthys of the genus Coregonus . Based on molecular data this is not a natural classification however, as the ciscoes are polyphyletic, comprising two different lineages within the freshwater whitefishes. [1]

Continental North American ciscoes: Coregonus artedi sensu lato

Eight taxa of cisco have been recognized in the Laurentian Great Lakes and other interior lakes of the once-glaciated North America. [2]

Usually, several taxa of ciscoes are found in a single lake. They exhibit different habitat distributions, feeding and breeding habits and morphological adaptations e.g. in their gill raker numbers. In the Great Lakes, at least five ciscoes coexist. [3]

According to genetic analyses, these cisco types do not represent unique, separate evolutionary lineages, but similar cisco morphs have evolved and attained their specific characteristics largely independently in each lake. Therefore, it has been suggested that they should not be recognized formally as distinct taxa, but all considered members of a single species, Coregonus artedi (sensu lato). [3] or Coregonus artedi complex. Nevertheless, for conservation and management purposes the sympatric morphs in each lake should be considered ESUs, evolutionarily significant units. [3] This taxonomic view is not widely accepted however, which has complicated discussions of the conservation status of some species. [4]

Ciscoes have been exploited in commercial fisheries, particularly in the Laurentian Great Lakes where the deepwater forms were the basis of the so-called chub fishery. The chub fishery had nothing to do with the various cyprinid fish species known as chubs but was exclusively based on the various species of ciscoes. The fishery continued as cisco stocks fell and non-native species such as sea lamprey, rainbow smelt and alewife spread through the system and increased in abundance. Alewife, in particular, have been implicated as a predator of cisco eggs and larvae, and as a competitor with ciscoes. The fishery shifted focus from species to species as cisco numbers declined and has been largely defunct for some years.

Bering cisco Lauretta whitefish.jpg
Bering cisco

Ciscoes of northwestern North America

Three species of cisco inhabit waters of the northwestern North America. These have been found to represent distinct evolutionary lineages, by genetic data. [3]

Eurasian ciscoes

The ranges of the three cisco species above extend across Beringia to the Asian coasts. Of those the Arctic cisco and least cisco (=sardine cisco) are widespread through northern Siberia. In the inland waters of northern Europe, the European cisco or vendace (Coregonus albula) replaces the Siberian sardine cisco. Some of the cisco lineages are genetically very close, such as the European and sardine ciscoes. Within some species, geographically separated populations have been treated as distinct taxa, despite close genetic relationships, such as the vendace and the pollan (Arctic cisco) on the British Isles. The European cisco has also evolved into ecologically distinct sympatric populations or ecomorphs independently within several lakes (e.g. autumn and spring spawning populations, normal and dwarf morphs), which have been designated as distinct taxa, making the systematics complicated as with the North American Coregonus artedi complex.

Phylogeny

Based on molecular data from mitochondrial DNA, the ciscoes comprise two distinct, unrelated groups: [1]

Related Research Articles

<i>Coregonus</i> Genus of fishes

Coregonus is a diverse genus of fish in the salmon family (Salmonidae). The Coregonus species are known as whitefishes. The genus contains at least 68 described extant taxa, but the true number of species is a matter of debate. The type species of the genus is Coregonus lavaretus.

<i>Coregonus lavaretus</i> Species of fish

Coregonus lavaretus is a species of freshwater whitefish, in the family Salmonidae. It is the type species of its genus Coregonus.

<span class="mw-page-title-main">Shortnose cisco</span> Species of fish

The shortnose cisco is a North American freshwater whitefish in the salmon family Salmonidae. One of the members of the broader Coregonus artedi species complex of ciscoes, it is native to the Great Lakes of Canada and the United States. Its population has been declining and it has disappeared from some of its earlier haunts. The last reported population was restricted to Georgian Bay off Lake Huron in Canada. It is thought that declines in the population of this fish may be linked with the arrival of the sea lamprey, in the Great Lakes. The International Union for Conservation of Nature has rated the conservation status of this fish as "critically endangered", and possibly extinct.

<span class="mw-page-title-main">Pollan (fish)</span> Species of fish

The pollan or Irish pollan is a freshwater whitefish known only from five Irish lakes, Lough Neagh, Lower Lough Erne, Lough Ree, Lough Derg and Lough Allen. The pollan faces competition from introduced species such as pike, roach and zebra mussel, and the populations rely on restocking for survival.

The longjaw cisco was a deep-water cisco or chub, usually caught at depths of 100 metres (328 ft) or more from Lakes Huron, Michigan, and Erie. Its Latin name was derived from Alpena, a city in Michigan. Silver colored and growing to a maximum length of about 30 centimeters long, the extinction of longjaw cisco was a result of overfishing, pollution of the Great Lakes and the disruption of Great Lakes food chains after the introduction of the sea lamprey.

<span class="mw-page-title-main">Blackfin cisco</span> Species of fish

The blackfin cisco was a North American salmonid fish in the freshwater whitefish sub-family Coregoninae. This silvery, deep-bodied fish with black fins, large eyes, a blunt snout and a terminal mouth, was one of the largest forms of ciscoes. The blackfin cisco used to inhabit the Great Lakes of North America until recently, but has been reported to have gone extinct. The blackfin cisco is a member of the C. artedi complex, whose taxonomy has not yet been resolved, and it may not represent a valid species.

<i>Coregonus albula</i> Species of fish

Coregonus albula, known as the vendace or as the European cisco, is a species of freshwater whitefish in the family Salmonidae. It is found in lakes in northern Europe, especially Finland, Latvia, Lithuania, Sweden, Russia and Estonia, and in some lakes of Norway, the United Kingdom, northern Germany, and Poland. It is also found in diluted brackish water in the Gulfs of Finland and Bothnia, both of which are in the Baltic Sea.

<span class="mw-page-title-main">Arctic cisco</span> Species of fish

Arctic cisco, also known as omul Russian: Омуль, is an anadromous species of freshwater whitefish that inhabits the Arctic parts of Siberia, Alaska and Canada. It has a close freshwater relative in several lakes of Ireland, known as the pollan, alternatively regarded as conspecific with it, or as a distinct species.

<i>Coregonus sardinella</i> Species of fish

Coregonus sardinella, known as the least cisco or the sardine cisco, is a fresh- and brackishwater salmonid fish that inhabits rivers, estuaries and coastal waters of the marginal seas of the Arctic Basin, as well as some large lakes of those areas.

<i>Coregonus hoyi</i> Species of fish

Coregonus hoyi, also known as the bloater, is a species or form of freshwater whitefish in the family Salmonidae. It is a silvery-coloured herring-like fish, 25.5 centimetres (10.0 in) long. It is found in most of the Great Lakes and in Lake Nipigon, and inhabits underwater slopes. This fish is not to be confused with the extinct deepwater cisco, a large fish that shared a common name with the bloater.

<span class="mw-page-title-main">Shortjaw cisco</span> Species of fish

The shortjaw cisco is a North-American freshwater whitefish in the salmon family. Adult fish range to about 30 cm (12 in) in length and are silver, tinged with green above and paler below. One of the members of the broader Coregonus artedi complex of ciscoes, it is distributed widely in the deeper lakes of Canada, but populations in the Great Lakes have been declining and it is no longer present in Lakes Michigan, Huron, and Erie. It feeds mainly on crustaceans and insect larvae and spawns in the autumn on the lake bed. It is part of the important cisco (chub) fishery in the Great Lakes. The International Union for Conservation of Nature has rated its conservation status as "vulnerable". Shortjaw cisco have however evolved from the cisco Coregonus artedi independently in different lakes and different parts of the range, and conservation assessments therefore should be made on a lake-wise rather than range-wide basis.

The kiyi is a species of freshwater whitefish, a deepwater cisco, endemic to the Great Lakes of North America. It previously inhabited Lake Superior, Lake Michigan, Lake Huron and Lake Ontario, but is now believed to persist only in Lake Superior where it is common. The various deepwater ciscos are also called chubs. The kiyi is part of the large group of related northern ciscos known as the Coregonus artedi complex.

<span class="mw-page-title-main">Freshwater whitefish</span> Subfamily of fishes

The freshwater whitefish are fishes of the subfamily Coregoninae, which contains whitefishes and ciscoes, and is one of three subfamilies in the salmon family Salmonidae. Apart from the subfamily Coregoninae, the family Salmonidae includes the salmon, trout, and char species of the subfamily Salmoninae, and grayling species of the subfamily Thymallinae. Freshwater whitefish are distributed mainly in relatively cool waters throughout the northern parts of the Northern Hemisphere.

<i>Coregonus artedi</i> Species of fish

Coregonus artedi, commonly known as the cisco, is a North American species of freshwater whitefish in the family Salmonidae. The number of species and definition of species limits in North American ciscoes is a matter of debate. Accordingly, Coregonus artedi may refer either in a narrow sense to one of the several types of cisco found e.g. in the Great Lakes, or in a broad sense to the complex of all ciscoes in continental North American lakes, Coregonus artedi sensu lato.

<span class="mw-page-title-main">Peled (fish)</span> Species of fish

The peled, also called the northern whitefish, is a species of freshwater whitefish in the family Salmonidae. It is found in northern Europe and Asia.

Coregonus trybomi is a freshwater whitefish in the family Salmonidae. It is a spring-spawning type of cisco, which probably has evolved from sympatric vendace independently in a number of Swedish lakes. Only one of those populations survives, and it is therefore considered Critically Endangered by the IUCN Red List. The status of Coregonus trybomi as a distinct species is however questionable. By Swedish authorities it is treated as a morphotype or ecotype, not an independent species. It was listed as "Data Deficient" in 2010 but excluded from the national red list in 2015.

Coregonus fontanae, also known as the Stechlin cisco, Fontane cisco, or Fontane's cisco, is a putative species of freshwater whitefish in the family Salmonidae endemic to the Großer Stechlinsee in northern Germany. It is believed to have recently evolved from the sympatric vendace, Coregonus albula.

<span class="mw-page-title-main">Bering cisco</span> Species of fish

The Bering cisco or Lauretta whitefish is a freshwater whitefish found in Alaska and part of Russia. It is often considered to be the same species as the more common Arctic cisco.

References

  1. 1 2 Bernatchez L, Colombani F, Dodson JJ (1991) Phylogenetic relationships among the subfamily Coregoninae as revealed by mitochondrial DNA restriction analysis Journal of Fish Biology 39 (Suppl A):283-290.
  2. Scott, W.B., Crossman, E.J. (1973) Freshwater Fishes of Canada. Bull. Fish. Res. B. Canada 184, 1–1092
  3. 1 2 3 4 Turgeon, J. & Bernatchez, L. (2003) Reticulate evolution and phenotypic diversity in North American ciscoes, Coregonus ssp. (Teleostei: Salmonidae): implications for the conservation of an evolutionary legacy Archived 2015-01-22 at the Wayback Machine Conservation Genetics 4: 67–81
  4. COSEWIC (2007). COSEWIC assessment and update status report of the blackfin cisco Coregonus nigripinnis in Canada Committee on the Status of Endangered Wildlife in Canada. vi + 23 pp
  5. Politov DV, Bickham JW, Patton JC (2004) Molecular phylogeography of Palearctic and Nearctic ciscoes. Ann. Zool. Fennici 41:13-23.