Thread: Panfish Growth

You don't need much magnification for otoliths, but the best way to look at them is crack them in half, sand the cracked edge with very fine sandpaper and have a light source to direct into the otolith to illuminate the rings. Sometimes they are pretty easy to read without cracking the otolith, but it depends on species, age of fish, etc. Scales are tough because they can be regenerated from traumatic events or just rubbing them off on objects which would make the fish seem younger than it really is. So you need a bunch of scales from the same fish to make sure you have the correct age and higher magnification for many species than otoliths. The older the fish is, the higher chance it has regenerated its scales in the past. For spines, you need a special saw to cut a very thin section to read. The attached picture is a spine section from a 56 inch, 92 pound blue catfish. Just an example of what they look like.