caudal fin

American  

noun

1. the terminal vertical fin of a fish.

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caudal fin British  

noun

1. the tail fin of fishes and some other aquatic vertebrates, used for propulsion during locomotion

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Example Sentences

They primarily rely on their dorsal fin, whereas strong swimmers use their caudal fin or back tail, Paig-Tran said.

From Los Angeles Times • Nov. 21, 2024

"Additionally, developmental changes suggest that vertebral anatomy shifts across development to support a larger body and caudal fin."

From Science Daily • Jan. 17, 2024

“It’s sort of unreal, when you come around the corner,” he said, looking skyward toward the caudal fin.

From The New Yorker • May 5, 2019

There’s a soft sway to its massive caudal fin as it serenely propels the animal forward through the endless blue.

From Scientific American • Aug. 30, 2017

The swordfish, when swimming at the surface, usually allows its dorsal fin and the upper lobe of its caudal fin to be visible, projecting out of the water.

From Tales of Fishes by Grey, Zane