The brown trout is a sleek, lean fish that is very powerful indeed, having a thick and muscular tail. They are indigenous to Europe and survive very well in the British Isles. In fact, no other freshwater fish is as widespread in this country as the brown trout. It can be found in the tiniest chalk streams of the south coast to the peaty tarns of the Scottish highlands. They are particularly prevalent in the vast loughs and lochs of Ireland and Scotland. The brown trout a real success story.
In running water they prefer to take up residence tight to a feature such as bridge supports or rocks, or even in the shallows where the water is heavily rippled to help disguise the fish.
In stillwater the brown trout will lay up deeper than that of the rainbow trout. And in some deep Scottish waters there can be found older brown trout that have turned predatory and often cannibalistic – these are known as ferox trout.
Brown trout are smaller than the rainbow trout, with the average being between 1-2lb and a monster being 20lb.
Ferox trout - pic supplied by Ceri Jones
The brown trout has all the classical salmonid features – an adipose fin set upon the root of the tail, a large dorsal fin, a thick a muscular tail and a sleek body shape. The tail is square or just slightly concave.
As the male brown trout grows, its lower jaw becomes to curve upwards slightly. During the spawning season the jaw will be even further pronounced, this is called a kype.
The colouration of the brown tout varies immensely. It can even vary between individual fish living in exactly the same circumstances in the same fishery.
Those fish that inhabit crystal clear chalk streams will tend to have a brown or even a gold back, slightly paler sides and a yellow, almost buttery, underside. They will be adorned with spectacular spots in either black, red or brown – sometimes all three colours – that are rung in white.
Stillwater brown trout living in reservoirs, vast rivers or man-made waters may well have silver flanks together with star-like shaped spots.
Like the rainbow trout, brown trout are very aggressive. They will feast upon crustaceans and insects that are at any stage of their life cycle. They will eat small fish too, including their own fry (called parr).
To catch a brown trout can be extremely easy if the fish are involved in a feeding frenzy. At those times you’ll easily catch them on spinners, small plugs and small spoons. Other baits that are renown to tempt brown trout are maggots and worms. But, often is the case, these baits are frowned upon and the only ‘true’ way to catch a brown trout is with fly tackle.
Here you’ll have to pick your fly lines and flies with a high degree of knowledge as you will have to present the right fly at the right depth to trick your quarry into taking it.
Brown trout breed in the depths of winter in highly oxygenated and shallow streams, over a bed of gravel. The female lays her eggs onto the gravel and immediately the male will fertilise them.
The life cycle of a brown trout is the same as all salmonid species: first the egg, then the alevin, then fry, then parr and finally the adult.