Smart Stuff with Twig Walkingstick: 'Rik!' Sting! Yow! (for the Week of July 22, 2007)

July 19, 2007


Q. Dear Twig: You said some fish make sounds. Well, last night my dad took me fishing. I caught a bullhead catfish. And you know what it did? It made sounds! "Rik-rik-rik!" Like that!

A. Bullhead catfish indeed can make sounds. And they do it a special way. Or at least in a different way than how most other fish that make sounds do it.

A common way for a fish to make sounds is to drum on the swimbladder inside its body with muscles or tendons or both. The sounds sound squeaky or tappy or drummy. Or clicky or ticky or poppy or moany. Grunty, even.

But bullheads do it another way. They do it with their pectoral ("PECK-ter-uhl") spines — pointy, venomous spines that bullheads stick out for protection.

How it works: The spines stick out then lock into place. They rub against the pectoral girdle, bones that link the spines to the skeleton. This rubbing makes a noise. It sounds like "Rik-rik-rik!"

Scientists call it a stridulation ("STRIJE-uh-LAY-shun") sound, a sound made by rubbing two body parts together. It's bullheadese for "Back off, buddy. Watch out for my venomous spines."

Twig

P.S. There's also a single spine on top, with the dorsal fin. A catfish's whiskers don't sting.

Notes: The common channel catfish has pectoral and dorsal spines as well. Many other catfish do, too. A catfish spine sting, sometimes called getting "finned," typically hurts like crazy, involves throbbing pain and possible swelling, and carries a risk of infection. Find treatment suggestions here: http://firstaid.webmd.com/wilderness_catfish_sting_treatment_firstaid.htm. Sources included the University of Massachusetts Amherst, http://www.bio.umass.edu/biology/conn.river/catfish.html; Wisconsin Natural Resources, http://www.wnrmag.com/stories/2007/feb07/catfish.htm; and Cornell University, http://www.cumv.cornell.edu/staff/friel.html (scroll down for sound files!).

About this column: "Smart Stuff with Twig Walkingstick," a free public service of The Ohio State University College of Food, Agricultural, and Environmental Sciences - specifically, of the Ohio Agricultural Research and Development Center (OARDC) and Ohio State University Extension, both part of the College - is a weekly column for children about science, nature, farming and the environment. The reading level typically rates at grades 3.5-4.5. For details, to ask Twig a question, and/or to receive the column free by mail or e-mail, contact Kurt Knebusch, CommTech, OSU/OARDC,1680 Madison Ave., Wooster, OH 44691, knebusch.1@osu.edu, (330) 263-3776. Online at http://extension.osu.edu/~news/archive.php?series=science.

Author(s): 
Kurt Knebusch
Source(s):