pelvic fin

American  

noun

1. (in fishes) either of a pair of fins on the lower surface of the body, corresponding to the hind limbs of a land vertebrate; ventral fin.

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pelvic fin British  

noun

1. either of a pair of fins attached to the pelvic girdle of fishes that help to control the direction of movement during locomotion

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Etymology

Origin of pelvic fin

First recorded in 1905–10

Example Sentences

"Our results show how the iconic deep-sea anglerfishes evolved from ancestors that walked along the ocean floor using modified pelvic fins," says Chase D. Brownstein of Yale University.

From Science Daily

The pelvic fins of fish are evolutionarily related to hind limbs in tetrapods -- four-limbed vertebrates, including humans.

From Science Daily

I drew a pectoral fin on the side and a pelvic fin on the bottom to help the shark move up and down.

From Literature

A few species of epaulette sharks have evolved to move their pectoral fins in the front and pelvic fins in the back to plod along outside the water at low tide.

From Seattle Times

These funny-looking fish latch onto rocks and seaweed, using a modified pelvic fin on their underside that acts like a suction cup to help them hang out until something tasty swims by.

From New York Times