In this next post I would like to talk about the elusive Brown Trout. The Brown Trout (Salmo trutta morpha fario and S. trutta morpha lacustris) and the Sea Trout (S. trutta morpha trutta) are fish of the same species distinguished chiefly by the fact that the brown trout is largely a freshwater fish, while the sea trout shows anadromous reproduction, migrating to the oceans for much of its life and returning to freshwater only to spawn.
The lacustrine morph of brown trout is most usually potamodromous, migrating from lakes into rivers or streams to spawn, although there is some evidence of stocks which spawn on wind-swept shorelines of lakes. S. trutta morpha fario form stream-resident populations, typically in alpine streams but sometimes in larger rivers, as well. There is evidence that anadromous and non-anadromous morphs coexisting in the same river can be genetically identical.
In common usage, the name “Brown Trout” is often applied indiscriminately to the various morphs. The brown trout is normally considered to be native to Europe and Asia but the natural distribution of the migratory forms may be, in fact, circumpolar. There are also landlocked populations far from the oceans, for example in Greece and Estonia. The fish is not considered to be endangered although, in some cases, individual stocks are under various degrees of stress mainly through habitat degradation, overharvest and artificial propagation leading to introgression. S. trutta morpha fario prefers cold, well-oxygenated upland waters, especially large streams in mountainous areas. Cover is important to trout, and they are more likely to be found where there are submerged rocks, undercut banks, and overhanging vegetation.
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. On the Bow River Brown Trout can weigh as much as 10-15 lbs. The current International Game Fish Association (IGFA) world “all tackle” record brown trout, 18.25 kg (40 pounds, 4 ounces), was caught in May of 1992 from the Little Red River, Arkansas by Howard “Rip” Collins. (Story with images) Brown trout may live for several years although, as with the Atlantic salmon, there is a high proportion of death of males after spawning and probably fewer than 20% of female kelts recover from spawning. The migratory forms grow to significantly larger sizes and may live longer.
Brown trout are active both by day and by night and are opportunistic feeders. While in fresh water, the diet will frequently include invertebrates from the streambed, small fish, frogs, 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 spinner and fly fishermen. Sea trout are especially fished for at night using all forms of terminal tackle as well as various types of flies. The spawning behaviour of brown trout is similar to that of the closely related Atlantic salmon. A typical female produces about 2000 eggs per kilogram (900 eggs per pound) of body weight at spawning.
Trout is a favourite food fish, and is used both fresh and smoked; there are many recipes for it, and it may be eaten fried, grilled, baked or microwaved. The specific epithet trutta derives from the Latin trutta, meaning, literally, “trout”. The Bow River has a healthy population of large Brown Trout. This species happens to be my favorate type of trout to fish for, as these fish are sometimes the most difficult species of trout to catch.