Salmo trutta : The Brown Trout we don't know

Every single day during the fishing season anglers across the globe are chasing brown trout around their waters and for good reason, they are an unbelievable gamefish. As fly fisherman we take things further than most as we try to understand our sport and our quarry.
Something I have noticed over the years however, is that we put so much emphasis on what the fish eat many people barely stop to try to understand the fish itself. Like anything else out there, you have to understand one thing to understand the next so why not publish something about the fish itself?

In the first part of this topic we will discuss the fish's basic biology and habitat requirements...

As many of us know, brown trout are not native to North America. Their native range includes and extends to Europe, the north part of Africa around the Atlas mountains, and western Asia around the Ural mountains which is their western most native range. They have been successfully introduced around the world and now thrive on every continent with the exception of Antartica. They were first introduced to the US by way of New York in the late 1800's.The historic native geographic range of the brown trout, Salmo trutta, is Europe, northern Africa, and western Asia. The northern range boundary includes Iceland, Scandanavia and Russia. The Pacific ocean marks the western boundary. The southern boundary is the coastline on the Mediterranean Sea including the islands of Corsica, Sardinia, and Sicily. Also marking a southern border is Atlas Mountain located in Northern Africa. Western range borders are the Ural Mountain range, considered to be the border between Europe and Asia. Today, the brown trout has been successfully introduced into waterways on every continent with the exception of Antarctica. The first brown trout in the western hemisphere arrived in New York in 1883, and are now found throughout most of the United StatesThe historic native geographic range of the brown trout, Salmo trutta, is Europe, northern Africa, and western Asia. The northern range boundary includes Iceland, Scandanavia and Russia. The Pacific ocean marks the western boundary. The southern boundary is the coastline on the Mediterranean Sea including the islands of Corsica, Sardinia, and Sicily. Also marking a southern border is Atlas Mountain located in Northern Africa. Western range borders are the Ural Mountain range, considered to be the border between Europe and Asia. Today, the brown trout has been successfully introduced into waterways on every continent with the exception of Antarctica. The first brown trout in the western hemisphere arrived in New York in 1883, and are now found throughout most of the United StatesThe historic native geographic range of the brown trout, Salmo trutta, is Europe, northern Africa, and western Asia. The northern range boundary includes Iceland, Scandanavia and Russia. The Pacific ocean marks the western boundary. The southern boundary is the coastline on the Mediterranean Sea including the islands of Corsica, Sardinia, and Sicily. Also marking a southern border is Atlas Mountain located in Northern Africa. Western range borders are the Ural Mountain range, considered to be the border between Europe and Asia. Today, the brown trout has been successfully introduced into waterways on every continent with the exception of Antarctica. The first brown trout in the western hemisphere arrived in New York in 1883, and are now found throughout most of the United States. Brown trou

Brown trout can reach sizes in excess of 30 inches and 20 pounds but throughout much of their range they average 12-14 inches. They can live to an old age of 20 years old but their average lifespan is probably around eight years depending on habitat, stressors in their home range and predation. Brown trout have large mouths where the jaw extends to or just beyond their eye allowing them to eat large prey items. Large breeding age males also develop a forward and/or downward facing protrusion of the upper jaw known as a kype. They have eight fins to include an adipose fin which is believed to cause increased maneuverability in fast flowing waters in which the fish often reside. In their natural environment they develop a dark olive back with brown and black spots while the lower half of the fish is tan to yellow in color. They have orange and red spots ringed in light blue as well as dark brown or olive spotting. As juveniles they lack the dense spotting of the adults but they do have parr marks. Parr marks are large ovals that run up and down the fish's flank and they disappear as they age. Parr marks used to be a determining factor when trying to identify wild fish compared to stocked fish but this is no longer the case. Brown's have large eyes and they can use them independently, meaning, they can basically see all of their field of view and be focused on all of it.

adipose fin

parr marks

Another cool feature about brown trout that most people do not know involves their teeth. If you've ever stuck your hand in a big trout's mouth you know they have teeth. Trout have a double row of teeth on the roof of their mouth which you can use to distinguish them from other species. In the northeast where I live, this can help you determine the difference between an Atlantic Salmon and a brown trout which can be difficult to do at times. Salmon will have a single row of teeth or possibly no teeth at all on the roof of their mouth. However, another fact about browns and all trout for that matter is that, according to some scientists, they are capable of breeding with salmon. Although this is rare a successful breeding could produce a hybrid fish.

http://www.maine.gov/ifw/fishing/species/identification/salmon_browntrout.htm