Blackfin cisco

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Blackfin cisco
FMIB 42893 Blackfin of Lake Michigan - Leucichthys nigripinnis (Gill).jpeg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Salmoniformes
Family: Salmonidae
Genus: Coregonus
Species:
C. nigripinnis
Binomial name
Coregonus nigripinnis
(Milner, 1874)

The blackfin cisco (Coregonus nigripinnis) 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.

Contents

Taxonomy

The species was first mentioned by P.R. Hoy 1872, attributing Gill as the species authority, but Gill's manuscript was never published. The first valid description of this species is attributed to James Wood Milner in 1874.

The taxonomy of C. nigripinnis, along with other ciscoes in the C. artedi complex, is unresolved. C. nigripinnis was recognized by W.N. Koelz in 1929 to consist of four subspecies, but he had difficulty distinguishing some specimens from C. kiyi . The subspecies he named were C. n. nigripinnis in Lake Huron and Lake Michigan, C. n. cyanopterus in Lake Superior, C. n. prognathus in Lake Ontario and C. n. regalis in Lake Nipigon. C. n. cyanopterus was later synonymized with C. zenithicus , and C. n. prognathus was declared a nomen dubium . Specimens from inland lakes in central Canada are generally regarded to be C. artedi.

Turgeon and Bernatchez proposed in 2003 to merge several cisco species, including the blackfin cisco, into the taxon C. artedi sensu lato . [2]

Description

It was a dark silvery color, with a dark green to black back, and pink or purple on the sides; the outer half of the fins was black. Blackfin ciscoes measured up to 510 mm (21 inches in length). Its preferred habitat was cold lakes at depths of up to 180 metres.

Decline

The decline of the species was largely caused by overfishing, which occurred during the 1950s as the result of mismanagement in an unregulated fishery, and predation from the invading sea lamprey. The introduced alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) were also aggressive predators of juveniles. Blackfin ciscoes were commercially fished until the early 1960s when declining stocks made the fishery uneconomic. Current threats to any remaining populations include commercial fishing, predation by rainbow smelt and interbreeding with lake herring (Coregonus artedi).

The blackfin cisco was last seen in Lake Huron in 1960 and in Lake Michigan in 1969. The last sighting of the previously-linked "cyanopterus" population was in 2006 in Long Lake near Thunder Bay on Lake Superior. This species may still be extant in Lake Nipigon. [2] The IUCN Red List lists it as extinct in 1996. The Committee on the Status of Endangered Wildlife in Canada listed it as threatened in 1988 and as data deficient in 2007, due to the uncertainty of its taxonomic status. Efforts are being made to consider reintroducing populations of cisco into the Great lakes, specifically Lake Michigan.[ citation needed ]

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.

<span class="mw-page-title-main">Cisco (fish)</span> Group of fishes

The ciscoes 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.

<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">Deepwater cisco</span> Species of fish

The deepwater cisco was one of the largest ciscoes in the Great Lakes. Its average length was 30 cm and it was about 1.0 kilogram in weight. Occurring only in Lakes Huron and Michigan, and inhabiting waters between 50 and 150 metres deep, it was difficult to distinguish from other ciscoes and was possibly the same species as the shortjaw cisco. The deepwater cisco was distinguished by usually having fewer than 33 gill rakers, relatively long pectoral fins, and unpigmented jaws. It was a silvery colour with a pink or purple lustre and a green or blue back. It spawned in August and September, earlier than most other ciscoes. Not much is known about its specific behaviors. Its diet consisted of Mysis relicta, fingernail clams, and various aquatic insects. Because of its large size, the deepwater cisco was heavily fished commercially.

<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">Rainbow smelt</span> Species of fish

The rainbow smelt is a North American species of fish of the family Osmeridae. Walleye, trout, and other larger fish prey on these smelt. The rainbow smelt prefer juvenile ciscoes, zooplankton such as calanoid copepods, and other small organisms, but are aggressive and will eat almost any fish they find. They are anadromous spring spawners and prefer clean streams with light flow and light siltation. The rainbow smelt face several barriers. They are weak swimmers and struggle to navigate fish ladders preventing them from making it past dams to the headwater streams where they spawn. The rise in erosion and dams helped to decimate the smelt population in the 1980s. There are currently plans to try to reduce damming and to help control erosion.

<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">Atlantic whitefish</span> Species of fish

The Atlantic whitefish is a coregonine fish inhabiting some freshwater lakes within Nova Scotia, Canada. It is known to survive only in the Petite Rivière watershed as landlocked populations. Earlier it was also found in the Tusket and Annis rivers of Nova Scotia. Those populations were anadromous, migrating to the estuary to feed while breeding in freshwater.

<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.

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.

<span class="mw-page-title-main">Lake whitefish</span> Species of fish

The lake whitefish is a species of freshwater whitefish from North America. Lake whitefish are found throughout much of Canada and parts of the northern United States, including all of the Great Lakes. The lake whitefish is sometimes referred to as a "humpback" fish due to the small size of the head in relation to the length of the body. It is a valuable commercial fish, and also occasionally taken by sport fishermen. Smoked, refrigerated, vacuum-packed lake whitefish fillets are available in North American grocery stores. Other vernacular names used for this fish include Otsego bass, Sault whitefish, gizzard fish, common whitefish, eastern whitefish, Great Lakes whitefish, humpback whitefish, inland whitefish and whitefish.

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

The Ives Lake cisco is a freshwater whitefish known to inhabit a single inland lake in the Upper Peninsula of Michigan. The species was last observed in 1983, although there is disagreement on whether it is distinct from Coregonus artedi. This taxon has been found only in Ives Lake, a lake in the Huron Mountains. The lake encompasses a radius of less than 1.5 miles (2.4 km).

Harp Lake is an oligotrophic, single-basin lake in Ontario, Canada. The lake covers over 710,000 m2 and has a depth of 37.5 m. Harp Lake does have dimitic stratification and is a temperate lake. Additionally, Harp Lake does not have anaerobic conditions in the water column because it is a relatively deep lake. The water in Harp Lake has a pH of 6.3. This pH is caused by the presence of acids and the lack of alkaline bases.[3] Slightly acidic lakes normally have a granite or siliceous bedrock and they are poorly buffered. Also, these lakes commonly have calcium-poor soils or thin soils.

References

  1. Gimenez Dixon, M. (1996). "Coregonus nigripinnis". IUCN Red List of Threatened Species . 1996: e.T5371A11124753. doi: 10.2305/IUCN.UK.1996.RLTS.T5371A11124753.en . Retrieved 19 November 2021.
  2. 1 2 Committee on the Status of Endangered Wildlife in Canada (2007). "COSEWIC assessment and update status report of the blackfin cisco Coregonus nigripinnis in Canada" (PDF). Retrieved 23 April 2016.