Blackfin cisco

Blackfin cisco
Conservation status
Extinct (IUCN 2.3)
Scientific classification
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) is 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, is one of the largest species of ciscoes. The blackfin cisco used to inhabit the Great Lakes of North America until recently, but has been reported to have gone extinct.

Description

It is a dark silvery color, with a dark green to black back, and pink or purple on the sides; the outer half of the fins is black. Blackfin ciscoes measure up to 510 mm (21 inches in length). Its preferred habitat is cold lakes at depths of up to 180 metres. The blackfin cisco was last seen in Lake Michigan in 1969 and in Lake Huron in 1960. The latest was seen in 2006 in Long Lake near Thunder Bay. Various sources state that the blackfin cisco is still occasionally sighted in Lake Nipigon in northern Ontario, and the status of the species in Canada and Ontario is still under review. However, the IUCN Red List lists it as extinct.

Decline

The decline of the species has been largely caused by overfishing and predation from the invading sea lamprey. The introduced alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) are also aggressive predators of juveniles. Blackfin ciscoes were commercially fished until the early 1900s when declining stocks made the fishery uneconomic. Current threats to the only remaining population include commercial fishing, predation by rainbow smelt and interbreeding with lake herring (Coregonus artedi).

References

• Gimenez Dixon (1996). Coregonus nigripinnis. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 10 May 2006.
• Froese, Rainer, and Daniel Pauly, eds. (2005). "Coregonus nigripinnis" in FishBase. 10 2005 version.
• "Coregonus nigripinnis". Integrated Taxonomic Information System. http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=623395. Retrieved 24 January 2006. 
• Parker, B. 1988. Status Report on the BLACKFIN CISCO, Coregonus nigripinnis, in Canada. Committee on the Status of Endangered Wildlife in Canada. 19 pp.