Trout Fins Are Designed for Efficient Swimming

Technology has allowed us to see the design of things in the natural world. Dr. Haibo Dong at the University of Virginia has used 3D computer models to study the turbulence created with each fin of a trout. American Scientist magazine states, “Interactions between swirling eddies created by a swimming trout show how its body is optimally laid out for energy-efficient movement.” Trout fins are designed for efficient swimming.

A trout’s body is shaped to swim through the water with less drag than any other shape. However, the role of various fins is not easy to see. Virtually all fish have a dorsal fin on the back and a caudal fin on the tail. Trout have other fins, including pectoral fins near their heads and pelvic fins near the center of their bellies. Toward the back of the trout’s body is a small adipose fin on top and an anal fin on the underside. The researchers have shown that the fin locations increase the thrust the tail produces. The anal fin produces 8.6% more thrust reducing the drag by 18.6%. Trout fins are designed for efficient swimming, or as the researchers conclude, “the whole trout is optimized for efficient swimming.”

Other fish have different fin arrangements to match their survival needs. A tuna living in the open ocean has a different layout of fins because it is designed for speed rather than efficiency. Fish that confine their existence to the bottom of a lake or river will not have the same fin layout as the tuna or the trout. For example, catfish have a fin arrangement designed for protection. Those of us who have grabbed a catfish incorrectly may have suffered a painful jab from its fins. Trout fins are designed for efficient swimming since they make long migrations, swimming upstream and sometimes over waterfalls.

Our technology allows us to understand the various designs seen in living things. Trout fishermen know that catching a trout differs from catching any other fish because of their mobility and muscular nature. Research has shown that the trout’s design shows wisdom right down to the shape and location of its fins. We suggest that this design is the product of a Designer, not just blind opportunistic chance. Genesis 1:21 tells us, “God created the great creatures of the sea and every living and moving thing with which the water teems..” Thanks to technology, we understand how over-simplified that statement is.

— John N. Clayton © 2024

Reference: “Fins Working Together” in American Scientist magazine for July-August 2024, pages 204-206.