Brown trout facts for kids
The brown trout (Salmo trutta) is a type of fish found in Europe. It's part of the salmon family. These fish have been moved to many places around the world where they can live well.
Brown trout can live in different ways:
- Some live only in fresh water, like rivers. These are called Salmo trutta morpha fario.
- Others live in lakes. These are called S. trutta morpha lacustris, also known as lake trout.
- Some travel to the ocean for most of their lives and only come back to fresh water to lay their eggs. These are called sea trout, or S. trutta morpha trutta.
Sea trout have different names in places like Ireland and Britain, such as sewin, finnock, or peal. Lake trout usually swim from lakes into rivers to lay their eggs. River trout stay in streams, often in mountain areas. It's interesting that sea trout and river trout living in the same river can be genetically identical. Scientists are still trying to figure out why some decide to travel to the ocean and others don't!
Quick facts for kids Brown trout |
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Salmo
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trutta
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Salmo trutta morpha trutta |
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Contents
About Brown Trout
The scientific name for the brown trout is Salmo trutta. The word trutta comes from Latin and simply means "trout." A Swedish scientist named Carl Linnaeus first described the brown trout in 1758. He also gave names to the river forms (Salmo fario) and lake forms (Salmo lacustris) of the brown trout.
Where Brown Trout Live
Brown trout naturally live in a wide area. This ranges from northern Norway and parts of Russia in the Arctic, down to the Atlas Mountains in North Africa. In the west, they are found in Iceland, and in the east, they reach areas like Afghanistan and Pakistan.
Brown Trout Around the World
Brown trout have been brought to many new places around the world. This includes North and South America, Australia, Asia, and parts of Africa. In many of these new places, the trout have created their own wild populations.
The first time brown trout were brought to Australia was in 1864. Out of 1500 eggs, 300 survived a long trip from England. By 1866, young trout were living in a hatchery in Tasmania. Soon after, they were released into the Plenty River and started a wild population. These Australian trout then helped introduce brown trout to rivers in New Zealand.
Brown trout were also successfully brought to South Africa in the 1890s. By 1909, they were living in the mountains of Kenya. In India, they were introduced to the Himalayas in 1868.
Brown Trout in the Americas
In Canada, brown trout were first introduced in 1883. Today, they live in most Canadian regions except for Yukon and the Northwest Territories. In South America, they arrived in Argentina in 1904. Now, you can find them in Chile, Peru, and the Falkland Islands.
A French geologist also brought brown trout to the remote Kerguelen Islands in the Indian Ocean. Only brown trout and brook trout survived there. Sea-run brown trout weighing over 20 pounds are often caught by anglers there.
In the United States, brown trout were first brought over in 1883. Eggs came from Germany and Scotland. These eggs were sent to different fish hatcheries. In April 1884, the first brown trout were released into the Baldwin River in Michigan. By 1900, brown trout had been introduced to 38 states. They adapted very well and created wild populations in most of these places.
Protecting Brown Trout
Brown trout are not considered an endangered species overall. However, some local groups of brown trout are facing problems. These problems are mainly due to their homes (habitats) being damaged, too much fishing, and mixing with farmed fish.
Sometimes, very warm water temperatures in summer can cause problems. This reduces the amount of oxygen in the water. If it stays warm for too long, local fish can die. This can get worse if rivers are polluted, often from farm fertilizers.
Overfishing is also a problem. If anglers catch too many large female fish and don't release them, fewer eggs are laid. This means fewer new fish will hatch.
Other introduced living things can also be a threat. For example, in Canada's Bow River, a type of alga called rock snot has spread. This alga covers the riverbed, making it hard for trout eggs to get enough water circulation. This can lead to fewer trout hatching and a decline in the adult fish population. Rock snot is thought to have spread accidentally on people's shoes.
These problems don't just affect brown trout. They can affect many or all species in a body of water, changing the whole ecosystem. In small streams, brown trout are important predators of small water bugs. If their numbers drop, it affects the entire food web.
Global climate change is also a concern. Brown trout like cool, well-oxygenated water. Scientists have found that brown trout numbers increased during colder times in history and decreased during warmer times.
Trout also need places to hide, like submerged rocks, logs, or overhanging plants. These spots protect them from predators, bright sunlight, and warm water. They also need access to deep water in winter or fast-moving water in summer to stay safe.
What Brown Trout Look Like
Brown trout have a slender, reddish-brown body. They have a long, narrow head. They are medium-sized fish. Some can grow to over 44 pounds (20 kg) and about 39 inches (100 cm) long. However, in smaller rivers, they are usually much smaller, often less than 2.2 pounds (1 kg). Lake trout can reach an average length of 16 to 31 inches (40-80 cm). The largest recorded brown trout weighed 41.45 pounds (18.80 kg). It was caught in Michigan in 2009.
Brown trout lay their eggs in a similar way to Atlantic salmon. A female typically lays about 2,000 eggs for every 2.2 pounds (1 kg) of her body weight.
Brown trout can live for up to 20 years. However, many males die after laying eggs. Fewer than 20% of female sea trout survive after spawning. The trout that travel to the sea grow much larger because there is more food in the ocean. Sea trout are more often female in rivers that don't have a lot of nutrients.
Brown trout are active both day and night. They eat whatever they can find. In fresh water, they often eat insects from the riverbed, other fish, frogs, mice, birds, and insects flying near the water. Because they eat so many insects, they are a favorite fish for fly fishing. Sea trout are often caught at night using special wet flies. Brown trout can also be caught with lures like spoons, spinners, or plastic worms. They also eat live or dead baitfish.
Freshwater brown trout can vary in color. Some are mostly silver with few spots and a white belly. Others are more brassy brown, fading to creamy white on their belly, with medium-sized spots surrounded by lighter rings. The silver ones can sometimes be mistaken for rainbow trout.
Brown trout rarely create hybrids with other fish species. If they do, the hybrid fish are almost always unable to have babies. One example is the tiger trout, which is a mix of a brown trout and a brook trout.
What Brown Trout Eat
Studies show that brown trout eat many different animals. Most of their food comes from insects and other small creatures living in the water. However, they also eat insects from land or other fish. As brown trout get bigger, their diet usually changes. Larger brown trout tend to eat more fish. This change in diet helps different sizes of trout in the same area find enough food.
When baby brown trout first hatch, their first meal is very important for their survival. They start eating even before they fully emerge from their eggs. Young trout eat small prey like tiny insect larvae.
Fishing and Farming Brown Trout
Brown trout have been widely introduced for sport fishing in many countries. This includes North America, South America, Australia, and New Zealand. In some places, like Australia, introduced brown trout have caused problems for native fish species.
Because brown trout are important for food and fishing, they are often raised in fish farms. They are then released into rivers and lakes. This means that truly wild populations, untouched by farmed fish, are probably only found in isolated places. For example, in Corsica or high mountain valleys in Europe.
Fish farms sometimes produce "triploid" brown trout. These fish cannot have babies. Anglers like them because they grow faster and larger. Some people think that stocking these fish is good because they won't mix with wild brown trout. However, triploid trout still compete with wild fish for food and space. They might also be more aggressive or disturb spawning behavior.
In recent years, sea trout populations in Scotland and Ireland have declined. This might be due to problems like sea lice coming from salmon farms.
Angling for Brown Trout
People in Europe have enjoyed fishing for brown trout for hundreds of years. The first mention of fly fishing for trout was by a Roman author around 200 AD. He described fishing for brown trout in Macedonia.
A famous book from 1496, Treatyse of Fysshynge with an Angle, talks about fishing for brown trout in English rivers. It says the trout is a "dainty fish" and a "fervent biter."
Another very famous book, The Compleat Angler (1653) by Izaak Walton, gives lots of advice about "the trout." Walton describes the trout as a "highly valued" fish that lives in "swiftest streams" and on "hardest gravel."
For centuries, authors writing about trout fishing were mostly talking about brown trout. When brown trout were brought to the U.S. in the 1880s, they became a big topic for American fishing writers too. In the late 1800s, an American angler named Theodore Gordon developed new ways to catch brown trout using dry flies in rivers like the Beaverkill.
Brown trout introduced to the Western United States created new fishing chances. One very successful introduction was in the Firehole River in Yellowstone National Park in 1890. An early account from 1897 describes catching these trout, noting their "large yellow spots encircled by black."
Today, brown trout introductions have created great fishing spots all over the U.S. and in other countries like New Zealand and Patagonia.
Images for kids
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A 2.7-kg (6 lb), 60-cm (2 ft) sea trout, from Galway Bay in the west of Ireland bearing scars from a fishing net
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Brown trout in a creek
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Brown trout in Värmland, Sweden, after the first summer
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A young brown trout from the River Derwent in North East England
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Brown trout from a western Wyoming creek
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waxworms
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Firehole river brown trout
- Froese, Rainer, and Daniel Pauly, eds. (2005). "Salmo trutta" in FishBase. 10 2005 version.
- Clover, Charles. 2004. The End of the Line: How overfishing is changing the world and what we eat. Ebury Press, London. ISBN: 0-09-189780-7
See also
In Spanish: Trucha común para niños
