The Alaska blackfish, Dallia pectoralis, is a fish that grows to 7" in length. It is elongate and cylindrical, with a dark olive-brown coloration. Four to six dark blotches run vertically along the sides, and the belly is white. The fins have reddish-brown speckles. Once thought to be herbivores, their primary diet is larvae of insects such as the midge and mosquito. They are found in swamps, ponds, lakes and streams with vegetation for cover, in tundra and forested locations not far inland. Their range is Alaska and the Bering Sea islands. Alaska Natives used to eat these fish and feed them to their dogs a great deal, catching them in the fall and freezing them for use over winter.
The hardiness of the Alaska blackfish is of mythical proportions. The fish survives the cold winters by moving to a depth of 7?8 meters when the surface becomes solid ice. Large gills protected by gill covers help them to survive the winters where the water temperatures drop to 0 °C (32 °F), including tales of reviving fish after they are frozen solid. Though the Alaskan blackfish can be supercooled for short periods at temperatures as low as ?20 °C (?36 °F) in controlled environment without contact with ice crystals, no Alaska blackfish has ever survived for even as much as an hour under these freezing conditions. Freezing any part of the body results in necrosis.
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