Jumbo spotted form of least cisco Coregonus sardinella in lakes of southern Yukon Territory

• Published in: Canadian Journal of Zoology
• Main Authors: Lindsey, C. C., Kratt, L. F.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1982
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Yukon; Four Lakes; Yukon river
• Online Access: http://dx.doi.org/10.1139/z82-356; http://www.nrcresearchpress.com/doi/pdf/10.1139/z82-356

Four lakes on the upper Yukon River drainage contain a strikingly spotted jumbo form of least cisco, with fork lengths up to 452 mm, larger than all previously known lacustrine or anadromous forms. The jumbo fish, with high gill raker counts (48–52), are probably nonmigratory. They may in each lake represent parallel responses to high dissolved solids, little competition, and unusually favourable conditions for growth. Available material is insufficient to establish whether small specimens in these lakes are young or slow-growing individuals of the jumbo spotted form, or whether the lakes contain two sympatric populations.