assume typical brook trout color and markings. Ecology and reproduction Diet Brook trout have a diverse diet that includes larval, pupal, and adult forms of aquatic insects (typically caddisflies, stoneflies, mayflies, and aquatic dipterans), and adult forms of terrestrial insects (typically ants, beetles, grasshoppers, and crickets) that fall into the water, crustaceans, frogs and other amphibians, molluscs, smaller fish, invertebrates, and even small aquatic mammals such as voles and sometimes other young brook trout Reproduction The female constructs a depression in a location in the stream bed, sometimes referred to as a "redd", where groundwater percolates upward through the gravel. One or more males approach the female, fertilizing the eggs as the female expresses them. Most spawnings involve peripheral males, which directly influences the number of eggs that survive into adulthood. In general, the larger the number of peripheral males present, the more likely the eggs will be cannibalized. The eggs are slightly denser than water. The female then buries the eggs in a small gravel mound; they hatch in 95 to 100 days. Angling The brook trout is a popular game fish with anglers, particularly fly fishermen. Until it was displaced by introduced brown trout (1883) and rainbow trout (1875), the brook trout attracted the most attention of anglers from colonial times through the first 100 years of U.S. history. Sporting writers such as Genio Scott Fishing in American Waters (1869), Thaddeus Norris American Anglers Book (1864), Robert Barnwell Roosevelt Game Fish of North America (1864) and Charles Hallock The Fishing Tourist (1873) produced guides to the best-known brook trout waters in America. As brook trout populations declined in the mid-19th century near urban areas, anglers flocked to the Adirondacks in upstate New York and the Rangeley lakes region in Maine to pursue brook trout. In July 1916 on the Nipigon River in northern Ontario, an Ontario physician, John W. Cook, caught a brook trout, which stands as the world record. Today, many anglers practice catch-and-release tactics to preserve remaining populations. Organizations such as Trout Unlimited have been at the forefront of efforts to institute air and water quality standards sufficient to protect the brook trout. Revenues derived from the sale of fishing licenses have been used to restore many sections of creeks and streams to brook trout habitat. The current world angling record brook trout was caught by Dr. W. J. Cook on the Nipigon River, Ontario, in