by James Morris
Illustrations by Talia Niederman

Today is Groundhog Day. The groundhog is not a hog, but actually a rodent. Specifically, it’s a large ground squirrel called a marmot. A close relative of the groundhog is the prairie dog, which is not a dog. What other organisms are misnamed?

In his essay, “The Misnamed, Mistreated, and Misunderstood Irish Elk,” the evolutionary biologist Stephen Jay Gould makes the wry observation that the Irish Elk is not really Irish and is not an elk. Instead, it’s a large deer that used to be found throughout Europe, Asia, and Northern Africa.

Similarly, Gould tells us that that the English horn isn’t English or a horn. It’s a woodwind from continental Europe.

The origins of these names and others can tell us interesting things about language and how we view the world. In this post, I thought it would be fun simply to share other misnamed organisms. I’ll leave it to you to help me figure out where these names came from and why they have stuck so tenaciously.

Starfish aren’t fish, which is why some scientists now call them sea stars. They are echinoderms and closely related to sand dollars and sea urchins.

Jellyfish aren’t fish either. Sometimes called “jellies,” they are formally called cnidarians.

Staying in the water, a whale shark is a shark, not a whale. It’s the largest living fish, hence the name.

And it turns out that crabeater seals, in spite of their name, don’t eat crabs. Instead, they eat krill, which are small marine invertebrates.

Blue-green algae are not algae, but a kind of bacteria. They are also called cyanobacteria. They were the first organisms capable of oxygenic photosynthesis, in which carbon dioxide combines with water to produce sugar, giving off oxygen as a by-product. As a result, oxygen accumulated in the atmosphere for the first time in the history of life on Earth, about 2.5 billion years ago. So, the next time you take a breath, you know who to ultimately thank.

Ringworm is a fungus, not a worm. It produces a characteristic ring-shaped rash on the skin.

Fireflies are beetles, not flies.

The Western red cedar is not a cedar. In fact, the Pacific Northwest has several species of trees called cedars, but none of them is a cedar. They don’t even look like cedars. Cedars (genus Cedrus) are generally found in the Mediterranean and Himalayas. The Western red cedar (genus Thuja) was used by George Pocock in the early 1900s to build crew shells for rowing teams, as recounted by Daniel James Brown in The Boys in the Boat.

Water bears aren’t bears. They are small 8-legged invertebrates that are also known as tardigrades. They can be found almost everywhere on Earth and are incredibly hardy. They made it through all five mass extinctions. They can survive extreme cold and heat, dehydration, high pressure (in the deep sea), UV radiation, as well as the vacuum of space (they were passengers on the Space Shuttle Endeavor and guests on the International Space Station).

Mountain goats aren’t goats, but they do live in the mountains and are fantastic climbers.

And, finally, like the Irish elk, Guinea pigs aren’t pigs and aren’t from Guinea. They are rodents, originally from the Andes.

© James Morris and Science Whys, 2017
Special thanks to Mariah Beck for coming up with many of these examples.