Fish

May 16, 2006

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Idaho's Native Fish Species!      from
What is a native species?
Where do native fish live?
Are all of the fish
in Idaho native?
What does it mean to be
non-native
?
Why did people introduce non-native fish in Idaho?
Where do non-native fish live?

Freah Water FishWhat is a native species?
     We say animals are native if their species has lived in the same place for a very long time. For example, cutthroat trout have been in Idaho for over one million years, so they are definitely native to Idaho. There are 39 species of fish that are native to Idaho.

     Native animals are important parts of the environment. They all do important jobs, or fill niches, in their habitat. For example, deer have an important job. They are nature's lawn mowers.
     Can you think of a job that one of Idaho's native fish does? Read about salmon's job.

Where do native fish live?Clean Water for fish     
     Most of our native fish live in cold, clean water. Cold water is different from warm water. Cold water can hold onto more oxygen then warm water. All fish need oxygen to breathe , just like you do, but they get it from inside the water. Oxygen inside water is called dissolved oxygen. Cold water can hold a lot of oxygen, so fish that live in cold water habitats usually have no problem getting all the oxygen they need. Cold water is also usually a bit cleaner and clearer.

     Trout like clear water, but they don't like to see their neighbors. Trout can live pretty close to each other. They just need enough food and a "wall" between them. Fallen logs or rocks make nice "walls" between neighbors. Good cold water habitats need fallen logs, rocks or other plants to give fish hiding places. Usually cold water is moving. The Boise River, Salmon River and Selway River would be examples of cold water habitats.

It's important to keep out water clear. Learn all about water quality
http://www.epa.gov/owow/monitoring/nationswaters/

Riffles-where the fish like to live
http://www.fs.fed.us/r4/boise/field_trip/creek/riffles.html
CatfishAre all of the fish in Idaho native?
     Not anymore. A long time ago, all of the fish in Idaho were native. But when settlers moved here, they brought non-native species to our state, such as brook trout, brown trout, catfish, crappie and blue gill.
What does it mean to be non-native?

     If you moved to Idaho from another state or country, you are a "non-native."
Sometimes, a plant or animal species can be a non-native too! People have moved both plants and animals to Idaho, sometimes on purpose and sometimes by mistake.
Why did people introduce non-native fish in Idaho?
     Most non-native fish were introduced into Idaho on purpose because people liked to catch them. When the settlers moved here they were used to catching certain fish, like brook trout and catfish. When they arrived in Idaho, those species of fish weren't here. Instead of changing what kind of fish they caught, the settlers decided to bring their favorite fish here. They let them go in Idaho's rivers and lakes, and now those non-native fish live here and reproduce on their own.
Where do non-native fish live?riffle
     Non-Native fish live in warm water.

      Many, but not all , of the non-native fish in Idaho like warm water habitats like shallow ponds and reservoirs. Warm water usually has less oxygen in it. The warmer water gets the harder it is for water to hold onto oxygen. Warm water usually has fish living in it that have interesting ways to get the oxygen they need.
     Catfish, called brown bullheads, are a species of non-native fish that you can find living in warm water. Bullheads can breathe through their skin. They can even use their air bladders as an emergency lung by coming up to the surface of the water and gulping air. They hold the air in their air bladders then "burp" the air out. The air can pass over their gills, so they can get oxygen out of the air. Pretty amazing!
     Warm water is usually murky. This is where the catfish's whiskers come in handy. Their whiskers help them find their way around and "smell" the water for food.
Water warm is usually still.

     Non-native fish live in cold water, too.
     Some non-native fish like to live in cold, clean streams and lakes. Our native fish prefer the same habitats. Usually one species of fish wins, or out-competes, the other species of fish for habitat.

     Cutthroat trout are Idaho's state fish! They are found from the Rocky Mountains west to the Pacific Ocean and from Alaska south to New Mexico. Cutthroat may live in small mountain streams, large rivers like the Snake River, or huge desert lakes. There are even cutthroat trout that spend part of their lives in the ocean! Some cutthroats live in very cold places like Stanley, Idaho and other cutthroats live in hot deserts. There are cutthroat trout that never get larger that six inches long. Other cutthroats may weigh more than 40 pounds. There are silvery cutthroat, golden cutthroat and cutthroat that look like rainbow trout. Some cutthroat have large spots; some have tiny spots. Still others have almost no spots at all.
     There are at least 14 subspecies, or types, of cutthroat trout living on the planet. But no matter what their names, shapes, sizes, colors or lifestyles, cutthroat all have one thing in common: the bright red slash marks under their throats, which is how they got the name cutthroat.

Spawning Salmon Native fish have important jobs, too. Salmon are fertilizer. Salmon swim all the way to the ocean and then back to Idaho's streams, where they spawn, or lay their eggs. They die very soon after spawning, and their decaying bodies fertilize our rivers, streams, lakes and forests. Microorganisms, tiny little animals, help decompose salmon flesh. These tiny animals then become food for small fish, even baby salmon. These small fish then become food for birds and other fish. When animals like bears and otters drag salmon into the woods to eat them, they are bringing nutrients into our forests.

     Salmon are the only way to move nutrients from the ocean back to our ecosystems in Idaho. All day, everyday, Idaho's rivers are carrying nutrients to the ocean. Without salmon, it would be a one-way trip for these essential elements.


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