Broad Whitefish, Coregonus nasus
Broad whitefish, Coregonus nasus.
This fish has a typical elongate whitefish body and is covered in silvery scales. However, where most other species are slim, the broad whitefish is heavyset and less tapered, with a blunter and more robust body. Its mouth points downward and is overhung by the upper lip. Its dorsal fin is separate, its often conspicuous adipose fin is fleshy, and its caudal fin is deeply forked. Located directly below the adipose fin are the anal fins, while the pelvic fins are directly below the dorsal fins. The pectoral fins are small and are positioned partly below the gill opening. Overall, the broad whitefish is silvery with a distinct greyish cast; its belly is silvery white or light yellow. Its "cheeks" often have brown, freckle-like spots, and adults broad whitefish have dark, almost opaque, fins.
The broad whitefish commonly occurs throughout Alaska, Siberia, and parts of northern Russia. It also occurs in the Perry River, NWT, and in numerous other Western Arctic river systems. There is little known about the biology of the broad whitefish because it is found strictly in the North, but anecdotal reports suggest that it spawns in midwinter and may live to 15 years or older. Food likely consists of bottom organisms such as aquatic insect larvae, small molluscs, and crustaceans.