Introduction | People | Fish | Habitat Activities | Index | Feedback | New Activities Fish Tags Biologists use several types of tags to mark and identify fish. The tag type used in this project is commonly known as a "Spaghetti Tag" due to its resemblance to the famous noodle. A sharp needle is used to insert the tag through the skin just under the dorsal fin on the fish's back. This procedure is much like getting your ears pierced. Each tag has a unique number and contains the address of the office to return it to. When fishermen catch a tagged fish, they are encouraged to return the tag to this office with information about where and when the fish was caught. This gives biologists a great deal of information including: how fast the fish traveled and the drainage it was traveling to. Back to the activity Text and graphics by USFWS staff Last modified 18 January, 2006