Meet Eight Species That Are Bending the Rules of Reproduction

Spice up your mating life with relationship tips from rock lizards, sharks and water fleas

In times of desperation, female sawtooth sharks have been known to reproduce sans males. For other species, solo reproduction is downright vanilla. (blickwinkel / Alamy)

When it comes to getting creative in the bedroom, we humans may think we’re the experts. In fact, we’ve barely scratched the surface of how varied and multifaceted reproduction can be—just look at species that do the deed through kinky-sounding strategies like sperm sequestration, "virgin births" via cloning or even hybridizing with other species. These may sound like show plots of a new series on the Space Channel, but they're actually just some of the many tricks that Mother Nature uses to stay a few steps ahead of Cosmopolitan Magazine's sex tips. 

Moreover, some of these unconventional methods are making scientists rethink the basic tenets of reproductive biology, says Ingo Schlupp, a professor of biology at the University of Oklahoma. His study subject, the asexual Amazon molly fish, defies the so-called rules of reproduction by making perfect clones of itself, sans males. With such a lack of genetic diversity, these finger-sized fish should have been wiped out by disease long ago, Schlupp points out. 

"How on earth do these guys survive for such a long time without any recombination?” he says. “To me that's a real head scratcher. Here's a species that doesn't [recombine their genes every generation] and theoretically should have been dead many thousands of generations ago, but yet they're living happily."

We still haven’t unraveled all the mysteries. But one thing's for certain: The more we learn about "alternative "reproduction strategies across species, the more we realize that many of them might not be so alternative after all. Now that they know what to look for, biologists are finding more and more cases of strange and hitherto unknown forms of animal procreation. In other words, baby-making outside the “traditional” male-female pairing could be far more widespread than we humans are inclined to think.

So why should all-female fish have all the fun? Spice up your mating life with these relationship tips from sharks, lizards and water fleas.

When the going gets tough, do the deed solo

In 2014, scientists at the National Aquarium facilities in Baltimore happened on something fishy. One of their female swellsharks had just laid eggs, which subsequently hatched into five baby sharks. Yet the mother shark in question had been isolated in captivity from males for at least three years. 

While at first researchers thought this might be a remarkable case of sperm storage—other specieshad been known to store viable sperm in their bodies—genetic testing later revealed the female had reproduced via parthenogenesis, which happens when an egg fuses with a byproduct of egg production to create a clone of the mother without any help from a male. Solo reproduction has been also been seen in sawtooth sharks, and is usually considered a last-ditch effort for a female to pass on her genes.

"There are so many things about sharks that are bizarre, unique and interesting," says David Gruber, a biologist at the City University of New York who has conducted research on biofluorescent swellsharks. Add one more thing to that list of novelties: Virgin births. Because apparently, glowing in the dark and inflating your body size to almost triple isn't enough to set you apart from your run-of-the-mill sharks. 

Editor's Note, March 28, 2017: This article initially stated that the Atlantic molly first became a separate species roughly 100 years ago.

About Joshua Rapp Learn
Joshua Rapp Learn

Joshua Rapp Learn is a D.C.-based journalist who writes about science, culture and the environment. He has crossed the Sahara Desert, floated down the Amazon River and explored in more than 50 countries.

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