Who isn’t a little weird? Here at the Center for Biological Diversity, we celebrate peculiarity in every one of its human and animal forms. After all, who’d want to live in a world without weirdness?

Desert Pupfish: Every Move They Make, All the Rules They Break

In this installment of Save the Weirdos: A frolicsome fish with an on-the-go lifestyle and an oxymoronic ability to thrive in the desert (it lives in water, after all).

Photo of male (blue) and female (brown) desert pupfish by Paul V. Loiselle/Wikimedia.

Desert pupfish got their name from their game.

In other words, pupfish were named for their resemblance to… puppies! (Hang with me for a sec.) Early pupfish researchers found the resemblance to puppies not in their appearance but in their behavior. Pupfish are so active they appear playful — like puppies.

As far as we know, these fish don’t actually play — but they move around so much, and in such interesting ways, that biologists have labeled and analyzed 15 of their most intriguing motor patterns, which happen to look and sound like things a young canine would do.

Some of these movements are mating behaviors. Like…

“Patrolling”: During breeding season an adult male pupfish will establish and defend a territory that he constantly patrols (like a guard dog), swimming back and forth in short spurts at its perimeters.

“Nuzzling”: If a male wants to mate with a female swimming along near the stream’s surface, he’ll approach her from below and nuzzle her abdominal region to show he’s totally sweating her.

“Nipping”: If the female is cool with the male’s attention, she’ll start nipping at the sand and gravel at the bottom of her habitat, dipping down to gobble up and then expel mouthfuls of sand and gravel bits — while the male tries to sidle up to her.

“Jerking” (like a puppy on a leash): If the female’s ready to get it on, the fish couple will align themselves in parallel “s-shapes,” at which point both fish jerk their bodies, usually causing the female to release an egg and the male to fertilize it.

Finally, after they’re done spawning — which can take up to two hours! — it’s the female who “flees” the scene — “Wham, bam, thank you, man!” — and the male often gives chase, which can totally look playful to a human watching.

Now let’s look at the other part of this species’ name: the word “desert.” When we think of fish, we don’t usually think “desert.” But these fish thrive where others can’t, in the shallow waters of desert springs, small streams and marshes. They historically ranged from the lower Colorado River in Arizona and California to the Gulf of Mexico and its delta in Sonora and Baja Mexico — and they still live in California’s Salton Sea.

One of their most badass attributes is the ability to survive not only in very high temperatures, but also when the water is extremely salty, acidic or low in oxygen. A freshwater fish that can survive in both fresh and salty water: like we said, badass.

Evidence shows that about 10,000 years ago, the American Southwest contained a series of linked desert lakes throughout which the pupfish may have “played.” But nowadays, the hardy desert pupfish struggles to stay alive against the threats of livestock grazing, water diversions and competition from nonnative species.

Learn lots more cool facts and help us save desert pupfish and other imperiled weirdos around the world. Then please join our email list, donate if you can, and make sure to LIKE this article by clicking the ❤ symbol to the lower left (only if you really like it, of course!).