Scientific Name: Salmo trutta
Ideal Temp: 65-75°F (18-24°C)
Environment: Lake, River, Stream
Technique: Casting, Fly
Lure Type: Flies, Spoons, Topwater
World Record: 41.45-lb (18.80-kg)
The brown trout is an originally European species of salmonid fish. It includes both purely freshwater populations, referred to Salmo trutta morpha fario and S. trutta morpha lacustris, and anadromous forms known as the sea trout, S. trutta morpha trutta. The latter migrates to the oceans for much of its life and returns to freshwater only to spawn. Sea trout in the UK and Ireland have many regional names, including sewin (Wales), finnock (Scotland), peal (West Country), mort (North West England) and white trout (Ireland).
The specific epithet trutta derives from the Latin trutta, meaning, literally, "trout". The lacustrine morph of brown trout is most usually potamodromous, migrating from lakes into rivers or streams to spawn, although evidence indicates stocks spawn on wind-swept shorelines of lakes. S. trutta morpha fario forms stream-resident populations, typically in alpine streams, but sometimes in larger rivers. Anadromous and nonanadromous morphs coexisting in the same river appear not to be genetically distinct. What determines whether or not they migrate remains unknown.
The brown trout is a medium-sized fish, growing to 20 kg or more in some localities, although in many smaller rivers, a mature weight of 1 kg (2 lb) or less is common. The spawning behaviour of brown trout is similar to that of the closely related Atlantic salmon. A typical female produces about 2,000 eggs per kilogram (900 eggs per pound) of body weight at spawning. On Sept. 11, 2009, a 41.45-lb (18.80-kg) brown trout was caught by Tom Healy in the Manistee River system in Michigan, setting a new state record. As of late December 2009, the fish captured by Mr. Healy was confirmed by both the International Game Fish Association and the Fresh Water Fishing Hall of Fame as the new all-tackle world record for the species. This fish now supplants the former world record from the Little Red River in Arkansas.
Brown trout can live to ages of 20 years. But as with the Atlantic salmon, a high proportion of males die after spawning, and probably fewer than 20% of anadromous female kelts recover from spawning. The migratory forms grow to significantly larger sizes for their age due to abundant forage fish in the waters where they spend most of their lives. Sea trout are more commonly female in less nutrient rich rivers. Brown trout are active both by day and by night and are opportunistic feeders. While in fresh water, their diets will frequently include invertebrates from the streambed, other fish, frogs, mice, birds, and insects flying near the water's surface. The high dietary reliance upon insect larvae, pupae, nymphs and adults is what allows trout to be a favoured target for fly fishing. Sea trout are especially fished for at night using wet flies. Brown trout can be caught with lures such as spoons, spinners, jigs, plugs, plastic worm imitations, and live or dead baitfish. Freshwater brown trout range in colour from largely silver with relatively few spots and a white belly, to the more well-known brassy brown cast fading to creamy white on the fish's belly, with medium-sized spots surrounded by lighter halos. The more silver forms can be mistaken for rainbow trout. Regional variants include the so-called "Loch Leven" trout, distinguished by larger fins, a slimmer body, and heavy black spotting, but lacking red spots. The continental European strain features a lighter golden cast with some red spotting and fewer dark spots. Notably, both strains can show considerable individual variation from this general description. Early stocking efforts in the United States used fish taken from Scotland and Germany. The Loch Leven strain is more often found in the western United States, while the "German brown" is found more toward the Midwest and East.
Brown trout rarely form hybrids with other species; if they do, they are almost invariably infertile. One such example is the tiger trout, a hybrid with the brook trout.
Lake dwelling brown trout are a wary lot. They hide in shallow water weed beds and rocky, boulder-strewn areas, and prefer a water temperature of 65-75 degrees F. Since brown trout spawn in tributary streams in September and October, they begin to take up residence near stream outlets in spring and early summer. After ascending a particular stream, brown trout spawners choose shallow, gravelly or rocky areas. The female creates a shallow depression (redd) in the gravel, in which the spawning fish deposit the eggs and sperm. When the process is completed, the female covers the redd with gravel. The average lake run adult weighs 8 pounds, although individuals can grow to be much larger. Young browns are preyed upon by larger fish and by predatory birds such as mergansers.