How to Identify Fish & Trout

With more than 20,000 species of fish in the world, identifying a species can be a bit of a headache. Many varieties of fish look the same, and when you're looking at a particular kind of fish like trout, the differences can be subtle. Fortunately the Internet provides several resources for identifying your fish.

Things You'll Need

  • Pen
  • Paper
  • Camera
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Instructions

    • 1

      Look at the color. One of the easiest ways to distinguish between types of fish is to examine their color and distinguishing marks, such as speckles, stripes and spots.

    • 2

      Check the size and shape. As with color, size and shape are two of the easiest markers for identifying fish. For example, Blueback trout are much thinner than Apache trout, and Lake trout have more pointed heads.

    • 3

      Examine the fins. Even within the same family, such as trout, larger fins can denote a specific variety. You also can look at the number of fins, as some species have more than others.

    • 4

      Consider the location. Some fish thrive in freshwater while others are found only in the ocean -- even within the same family. For example, Brook trout are found in lakes and streams, while Blueback trout are mostly found at sea. The habitat of the fish you are trying to identify can tell you a lot about its species.

    • 5

      Write down your findings, or take a picture. This will help you keep a record of what you discover.

    • 6

      Compare your findings. After you have carefully examined the fish, compare your findings to a website that has a large variety of fish species with accompanying pictures (see Resources). If you still have difficulty, try visiting a museum or local fish club and asking someone who has a good knowledge of fish.