Aurora Trout

Description
Habitat
Threats
Further Information
Scientific Information

Description
The Aurora Trout (Salvelinus fontinalis timagamiensis) is a unique variant of the Brook Trout, distinguished by its colouration. It is a member of the Trout and Salmon family (Salmonidae) and has the following characteristics:

• Looks similar to Brook Trout, yet adult fish lack the yellow marks throughout the dorsal region and exhibit few to no red spots with blue halos;
• Dorsal surface is typically olive green to dark brown with iridescent steel blue and silver sides and silvery white underparts that are often tinged with pink;
• Anal, pelvic and pectoral fins with a white leading edge followed by a dark stripe, the rest of the fins are reddish;
• Caudal fin nearly straight or with a shallow indentation;
• The largest known Aurora Trout was 3,500 g and 600 mm long.

In 2011, the Aurora Trout was determined by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) to be ineligible for assessment as it did not satisfy the discreteness and significance criteria that would justify its recognition as a designatable unit within Brook Trout. Similarly, it is no longer considered eligible to be designated as a species of risk under Ontario’s Endangered Species Act, 2007 (2011). Reassessment of the species’ status under the federal Species at Risk Act is currently underway.

Salvelinus fontinalis timagamiensis

Illustration of an Aurora Trout ©Cory Trepanier

Habitat
The Aurora Trout was native to a few remote, high-elevation lakes in the Temagami district of Ontario, Whirligig Lake and Whitepine Lake, located north of Sudbury. The original native populations were extirpated as a result of lake acidification in the 1960s. Using captive breeding stock, the Aurora Trout were re-introduced into the lakes in the 1990s following improvements in water quality, and have since become self-sustaining populations.  It is also stocked in other lakes in northern Ontario. Natural reproduction by Aurora Trout introduced in two non-native lakes is limited.

The Aurora Trout is a coldwater species found in clear, cool lakes. Spawning occurs in late October to early November over rubble, sand and gravel in water up to 4 m deep. Females construct redds and embryos are buried in the substrate. Groundwater upwellings are likely important spawning areas. Sexual maturity is reached at two to four years. Aurora Trout have a lifespan of approximately eight years.

Distribution of the Aurora Trout in Canada. Red dots indicate the native populations. Black dots indicate the introduced populations.

Threats
The Aurora Trout was lost from its natural range due to acid precipitation that disrupted reproduction. Low pH from acid precipitation and runoff is a continuing threat to the Aurora Trout. They are also likely affected by limited habitat (particularly a lack of groundwater springs for spawning and necessary elements for thermal refuge). Inbreeding, resulting from the small genetic pool of captive individuals, is also likely contributing to long-term threats to its viability. 

Further Information:
The recent 2011 COSEWIC re-assessment of the Aurora Trout.

Scientific Information:

Scientific Name: Salvelinus fontinalis timagamiensis
SARA Status: Endangered
COSEWIC Status: Ineligible for assessment