Brook Trout

Identification

White leading edges on the lower fins are the giveaway. Worm-like pale vermiculations run over the back and dorsal fin, and the flanks carry red spots ringed with blue halos — brown trout have red spots with pale halos, never blue. Spawning males colour to fiery red along the lower flank with black pigment, and develop a kype.

Habitat & Range

Cold, clean, well-oxygenated streams, spring ponds and lakes. Requires water below about 68°F for sustained periods and oxygen at 5 ppm or better; retreats to headwaters and spring seeps as summer water warms.

Native to eastern North America from Labrador and Quebec through the Great Lakes and down the Appalachians; widely introduced in the western US and abroad. Anadromous "salter" populations feed in estuaries for 40 to 90 days a year.

Diet & Feeding

Aquatic insects, terrestrials, crustaceans and small fish. Opportunistic and less selective than brown trout, which is why they are the classic small-stream fish for a new angler.

Spawning & Reproduction

Autumn spawner, from late September into November, and in some shore-spawning ponds from mid-November into January. The female digs a redd 4 to 12 inches deep in gravel sited over upwelling groundwater — the upwelling keeps eggs from freezing and supplies oxygen through the winter. Unusually among salmonids, courtship and spawning happen in daylight.