Differential Interference Contrast Image Gallery

Ctenoid Fish Scale

Similar to trees, the age of a fish may be estimated by examining growth rings on its ctenoid scales. This is because as a fish grows, so does its scales. The increase in size leaves rings, known as circuli, which are similar to those that appear in tree trunks. In winter months or other periods of cold weather, the growth rate of fish and their scales decelerates. Consequently, the circuli occur at much smaller intervals, which leaves a dark band. By counting the bands, known as annuli, an approximate age of a fish may be obtained.

© 1995-2019 by Michael W. Davidson and The Florida State University. All Rights Reserved. No images, graphics, software, scripts, or applets may be reproduced or used in any manner without permission from the copyright holders. Use of this website means you agree to all of the Legal Terms and Conditions set forth by the owners.
This website is maintained by our
Graphics & Web Programming Team
in collaboration with Optical Microscopy at the
National High Magnetic Field Laboratory.
Last modification: Monday, Dec 01, 2003 at 02:02 PM
Access Count Since April 22, 2003: 9794
Microscopes provided by:
Visit the Nikon website. Visit the Olympus Microscopy Resource Center website.