Aquatic Species at Risk - The Shortnose Cisco

Description
Habitat
Threats
Further Information
Scientific Information

Description
The Shortnose Cisco (Coregonus reighardi) is one of 10 cisco species found in Canada. It is a member of the Salmonidae family and has the following characteristics:

• Short head;
• Small eye;
• Small snout with distinctly dark pigmentation;
• Small terminal mouth with lower jaw included in the upper jaw;
• Gill raker count of 32 to 42;
• Silvery in appearance;
• Maximum weight 420 g; and
• Total average length of 265 mm.

©  Illustration Paul Vescei

Habitat
Historically found in Lake Huron, Lake Michigan and Lake Ontario, it is believed that the Shortnose Cisco may now be extinct. It has not been recorded in Lake Ontario since 1964, Lake Michigan since 1984 nor Lake Huron since 1985.

Very little is known about the habitat preferences and life history of the Shortnose Cisco. It was a deepwater fish, considered one of the ‘chub’ species, which lived in clear, cold-water environments all year long. It has been collected in water depths ranging from 22 to 110 m. The Shortnose Cisco was the only known spring-spawning cisco in the lakes where it occurred and likely migrated to deep water for spawning. There is some evidence that fall spawning may have also taken place. Sexual maturity was reached at two to three years. The maximum age was eleven years for females and nine years for males. It was prey for Burbot (Lota lota) and deepwater forms of Lake Trout (Salvelinus namaycush).

Distribution of Shortnose Cisco in Canada.

Threats
Overfishing, ecosystem changes and interbreeding (hybridization) with other ciscoes have all been implicated in the decline of the Shortnose Cisco. Commercial overfishing, starting in the late 1800s, had the most immediate and profound effect on the Great Lakes cisco populations, leading to the collapse of the chub fishery by the 1930s. The introduction of non-native species into the Great Lakes may have furthered the decline of the Shortnose Cisco, along with other native fish stocks. In particular, competition and/or predation from Sea Lamprey (Petromyzon marinus), Alewife (Alosa pseudoharengus), Rainbow Smelt (Osmerus mordax) and more recently Zebra and Quagga mussels (Dreissena spp.) have either contributed to the decline of the Shortnose Cisco, or have impeded its re-establishment. Hybridization between the Shortnose Cisco and other deepwater cisco species is also suggested as hastening its decline.

Further Information:
For further information, visit the SARA Registry at www.SARAregistry.gc.ca or www.COSEWIC.gc.ca.

Scientific Information:

Scientific name:  Coregonus reighardi
SARA Status: Endangered (December 2007)
COSEWIC Status: Endangered (May 2005)