7634

• UCREFRP Catalog Number: 7634
• Author: U.S. Fish and Wildlife Service.
• Title: Threatened Wildlife of the United States.
• USFW Year: 1973.
• USFW - Doc Type: Washington, D.C.
• Copyright Material: NO

BLACKFIN CISCO Coregonus n. nigripinnis (Gill, 1872)
Order: SALMONIFORMES Family: SALMONIDAE
Significance: The blackfin cisco is the largest cisco of the Great Lakes, and was a very
important commercial species in the early fishery .
Distinguishing characteristics: Distinguished by its large size and deep body, the very
dark coloration of the fins and back, and high number of gill rakers .
Present distribution: Unknown if extant in Lakes Michigan and Huron, the only lakes
where the typical blackfin cisco was found . Subspecies of uncertain relationship under
present taxonomic concepts have been reported from Lake Ontario (C , n_. prognathus ,
considered since the early 1900's) and Lakes Superior (C, n_. cyanopterus) and Nipigon
(C. n_. prognathus) in greatly reduced numbers. The blackfin cisco has been reported
from lakes of Ontario, Manitoba, and Saskatchewan, but their relation to the blackfin of
the Great Lakes is uncertain .
Former distribution: The typical blackfin (C. n_. nigripinnis) was only found in the
deepest waters of Lakes Michigan and Huron.
Status: At least seriously depleted, although probably extinct. Last specimen taken in
Lake Michigan in 1955. None seen subsequently in fishery surveys of Lakes Michigan and
Huron .
Estimated numbers: Unknown .
Fecundity: Believed to have spawned in deeper waters in midwinter . Matured at a
greater age and size than other ciscoes .
Reasons for decline: The decline in the early 1900's was probably due to intensive
commercial fishery . Present decline and disappearance due to sea lamprey predation and
continued heavy fishing for larger ciscoes during the 1940's and 1950's .
Protective measures already taken: None .
Measures proposed: If a relict stock is found, they might be transferred to a remote lake.
Number in captivity: None .
Culture potential in captivity: Unknown .
Remarks: Data submitted by Dr. Stanford H. Smith, Bureau of Commercial Fisheries,
Ann Arbor, Michigan. Dr. Stanford Smith has stated that "....the last record of the
blackfin cisco was in 1955."
References
Hile, R. and H. J. Buettner. 1955. Commercial fishery -for chubs (ciscoes) in
Lake Michigan through 1953. U . S . Fish and Wildlife Serv . , Spec . Sci .
Rept.--Fish. (163):49.
Koelz, W . 1929. Coregonid fishes of the Great Lakes . Bull . U . S . Bur . Fish .
43, 1927:297-643.
12