Feet Paddle Efficiently

photograph of platypus swimming in water

Biological Strategy

Platypus

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Move in/on Liquids

Water is not only the most abundant liquid on earth, but it’s vital to life–so it’s no surprise that the majority of life has evolved to thrive on and under its surface. Moving efficiently in and on this dense and dynamic substance presents unique challenges and opportunities for living systems. As a result, they have evolved countless solutions to optimize drag, utilize surface tension, fine tune buoyancy, and take advantage of various types of currents and fluid dynamics. For example, sharks can slide through water by reducing drag due to their streamlined shape and specially shaped features on their skin.

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Mammals

Class Mammalia (“breast”): Bats, cats, whales, horses, humans

Mammals make up less than 1% of all animals on earth, but they include some of the most well-known species. We know first-hand some of the characteristics that make mammals unique, like having hair, being able to sweat, and producing milk through mammary glands. Another critical shared feature is a set of highly-specialized teeth. Unlike sharks or alligators, for example, whose teeth are generally all the same size and shape, mammals have differently shaped teeth in different areas of the jaws to target specific foods or foraging strategies.

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The front feet of a platypus provide exceptional paddling power thanks to extensive webbing.

Image: Elonnon / CC BY SA - Creative Commons Attribution + ShareAlike

Close-up view of platypus foot with webbing

Image: John Lewin / Public Domain - No restrictions

Platypus

“The rear toes [of the platypus] are webbed like those of a duck; but the front feet are unique. The web extends along the sides of the feet and under, and beyond, the claws on all the toes. This more than doubles the surface area, and thus the paddling power, of the foot.” (Foy 1983:182)

Last Updated April 7, 2018

References

Book

The grand design: Form and colour in animals

01/01/1983 | Sally Foy

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