Trout

Trout are a group of fish that live in freshwater, such as lakes, rivers, and wetlands. They belong to several groups including Oncorhynchus, Salmo, and Salvelinus, and are part of the salmon family. Though they look similar to salmon, most trout spend their whole lives in freshwater, moving between smaller creeks and larger water bodies at different stages of their lives.

Some trout species, like the steelhead and sea trout, do travel to the ocean for part of their lives before returning to freshwater to have babies, much like salmon. Trout are important both as food for people and as a key part of the food chain in water. They eat smaller creatures such as insects, crustaceans, and small fish, while also being eaten by animals like brown bears, otters, and various birds.

Because trout play a vital role in their homes, they help keep the balance of nature in both water and on land. Their remains provide nutrients for plants and other animals living near water. Trout are admired for their beauty and are popular among people who enjoy fishing, making them both important to nature and to people.

Species

The name "trout" refers to many kinds of fish in three groups in the subfamily Salmoninae: Salmo, Oncorhynchus, and Salvelinus. Some well-known trout include the Brown trout, Rainbow trout, and Brook trout. People enjoy fishing for these fish, and they live in many freshwater places.

Other fish sometimes called trout, like the Spotted sea-trout, are from different families but look similar.

Anatomy

Trout living in different places can have different colors and patterns to blend in. When they are ready to mate, their colors become very bright. Trout have soft fins without sharp spines and a small fatty fin near their tail. They also have a special air-filled organ called a swim bladder connected to their throat, which helps them stay balanced in the water.

There are many kinds of trout, and some look quite different from each other even though they are closely related. For example, in the eastern United States, the brook trout, aurora trout, and the silver trout look different but are actually the same species. Lake trout, found in big lakes in North America, can live for many decades and grow very large, much bigger than rainbow trout, which usually live about seven years.

Habitat

Trout are coldwater fish that live in cool, clear streams, wetlands, and lakes. They are found naturally in North America, northern Asia, and Europe. In the 19th century, people brought some trout to Australia and New Zealand. They became popular with people who fish, but they also changed where some native fish lived, such as the climbing galaxias. Some similar trout can be found in the Himalayan Region and the Tian Shan mountains.

Diet

Trout eat other fish and small water animals like flies, mayflies, caddisflies, stoneflies, mollusks, dragonflies, and zooplankton. When they get bigger, they hunt other fish, sometimes eating fish up to one-third their own length.

Trout also like to eat land animals like insects and small animals that fall into the water, such as mice. They have a varied diet, which includes aquatic life like minnows and crawfish, making their eating habits very flexible.

Trout as food

Trout is a popular food fish with tasty, tender flesh like salmon. Its flavor changes depending on what the trout eats. Trout raised on fish farms are often put into rivers and lakes for people to catch.

Trout meat can be cooked in many ways, such as smoking. In some places, farm-raised rainbow trout has been sold as salmon, raising concerns about food labeling.

Nutritional value

A serving of trout, about 79 grams or 2.8 ounces, gives good protein and low fat, plus other nutrients. Here’s what you’ll usually find in one fillet:

• Energy: 490 kJ (117 kcal)
• Fat (g): 5.22
• Carbohydrates (g): 0
• Fibers (g): 0
• Protein (g): 16.41
• Cholesterol (mg): 46

Trout fishing

Trout are popular fish for people to catch because they fight hard. Fishers use special baits and lures that look like the small animals trout eat, such as insects and small fish. There are different ways to fish for trout, like using a normal fishing rod or trying fly fishing, where special lightweight lures are used.

Trout can be found in rivers, lakes, and even under ice in winter. Some of the biggest trout ever caught include a lake trout from Great Bear Lake in Canada and a rainbow trout from Lake Diefenbaker in Canada. Fishers use many kinds of bait, such as waxworms, corn worms, and small flies, to attract trout.

Declines in native trout populations

Many native trout are having a hard time because of a few big challenges. These include invasive species, wildfires, and climate change.

People brought in fish that were not from the area to make fishing better. But these new fish often take over and push out the native trout. They can also mix with native trout, which changes the original trout families.

Climate change is also a problem for trout. When temperatures get too warm, especially in rivers and lakes, it is hard for trout to live. They need cooler water to stay healthy. People are working to help protect native trout, like using special fish in hatcheries to stop unwanted mixing of genes.