comScore Male Guppy Sperm Actually Travels Faster For Sisters | The Mary Sue
Skip to main content

Male Guppy Sperm Actually Travels Faster In The Prescence of Their Sisters

The things I do for prolonging our genetic line.


cersei jaime

Inbreeding is generally thought of as a bad thing, because for most species it is. Even if we set aside the ickiness, most species thrive best with a higher gene variation, which you don’t get after sleeping around within your own gene pool for a few generations. Except guppies, apparently. Male guppies are aaall about the sister sex.

While studying the rate of ejaculation between courtship of male guppies and related and unrelated females (you know, just a regular Friday night), scientists from the Centre for Evolutionary Biology at The University of Western Australia were expecting that these guppy bros would be more enthusiastic in the presence of a new guppy lady. Not necessarily so!

While they do put more time and energy into wooing unrelated females, male guppies actually produce ejaculate with faster sperm when paired with their own sisters — meaning that they can not only recognize the difference between relatives and non-relatives, but every once in a while they find their own flesh and blood super hot.

“We interpret this latter finding as evidence for sexual conflict because in guppies females exhibit ‘preferences’ for unrelated sperm,” Professor Jon Evans said.  “By producing more competitive sperm when mating with siblings, male guppies may potentially circumvent the females’ natural preference to avoid inbreeding.”

That’s right: male guppies have a higher tolerance for inbreeding than female ones. Presumably because once the kids get born, Daddy gets to swim around with the guppy Kingsguard and let some other chump deal with the psychotic fruit of his fishy-loins, and Mom has to pick up all the pieces while getting her parenting skills insulted the whole time.

(via, image via HBO)

Meanwhile in related links

Have a tip we should know? [email protected]

Filed Under:

Follow The Mary Sue: