What Is It?

This key is a tool designed to allow you to identify the family of any fish found in Puget Sound. It is an "artificial" key, which means that the order of families in the key does not always follow taxonomic order. That's because the traits scientists use to determine evolutionary relationships are often internal characters or developmental processes. This key is based instead on external characters, so that specimens can be identified without dissection. For a look at the taxonomic order of Puget Sound fishes, click on "Taxonomic List."

Keying a Specimen

This is a dichotomous key (dichotomous means "dividing into two parts"). At each step in the key, you will have two choices, a or b . Read the two options and determine which one applies to your specimen. Once you decide which choice fits your fish, look at where the key tells you to go. If you see a number, jump down to that number within the section you are in and proceed from there. If you are directed to a new section, click on the link to that section and begin on number 1 of the new section. If the key gives you the name of a family, congratulations, you are done! Click on the family name for more information on the family. Always start keying a specimen from number 1 of Section A.

Biologists use the term "character" when referring to any observable trait an organism has. Some of the terms and characters used in this key may be new to you. Before you try keying out a fish, you might want to click on "Glossary" for definitions of selected terms. You will notice, as you proceed through the key, that some of the terms are links. Click on the link to get a definition of the term. The definition will pop up in a new window, so you won't lose your place in the key. Also, notice that a term is usually linked to its definition only the first time you encounter it.