A Fin with a Function


Featured in Answers Magazine

The fish in many fish families have a small fin on their backs, called an adipose fin, located between the large dorsal fin and the tail fin. For years researchers believed the fin was a useless leftover from the fish’s supposed evolutionary past, so at salmon hatcheries they would clip the fins as a harmless way to mark each fish so they knew where it spawned.

But a marine biologist in Canada noticed that fish jerked when the fin was cut. After further investigation, he discovered that these fish had to work harder to swim, putting the altered salmon at a disadvantage in the wild.

In fact, the adipose fin contains a network of nerves that likely serves as a sensory organ. Clipping the fin may decrease the salmons’ ability to navigate turbulent waters.1

In this instance, it looks like evolutionary assumptions led hatcheries to handicap the very fish they had hoped to save.


© Mark Toohey. All rights reserved.

Recently marine biologists noticed the importance of a seemingly useless small fin on the backs of salmon.

Answers Magazine

January – March 2012

How can we construct safer buildings? How can we clean up emissions from power plants? Increasingly, engineers are turning to God’s original designs in nature to solve difficult engineering problems. What a testimony to our wise and caring Creator! Also, learn how God is using Amish believers in the USA to help build a new full-size Ark. Plus, discover what the Bible says about those mysterious giants, the Nephilim.

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  1. “Clipped Fins Hamper Hatchery Salmon,” July 11, 2011, http://www.timescolonist.com.


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