Weird: Scientists discover oral sexual encounters in spiders

Normally, I would not carry a science story like this, but it is just so weird, it seemed worth noting. Those with arachnophobia need not read this.

Darwin's Bark Spider

Darwin’s Bark Spider

Matjaz Gregoric, a research associate at the Scientific Research Centre of the Slovenian Academy of Sciences and Arts (ZRC SAZU), Jovan Hadzi Institute of Biology, and coauthors studied the mating behavior of the Madagascan Darwin’s bark spider (Caerostris darwini), a sexually size dimorphic species from Madagascar with females several times larger and heavier than males. They uncovered a rich sexual repertoire in C. darwini that predictably involved sexual cannibalism and genital mutilation. In addition, their surprising finding was that males of this species routinely salivate onto female genitalia.

“Oral sexual contact seems to be an obligate sexual behavior in this species as all males did it before, in between, and after copulations, even up to 100 times.” said Gregoric who led the field and laboratory work that resulted in the current publication. Matjaz Kuntner, the senior author on this paper and chair of the Jovan Hadzi Institute of Biology ZRC SAZU only recently discovered and described C. darwini, noting that it produces nature’s largest webs and toughest silk. Now, this intriguing finding adds sexual behaviors to the species’ natural history.

Oral sexual contact is rare in the animal kingdom, except in mammals, where fellatio-like behaviors are known in macaques, lemurs, bonobos, hyenas, cheetahs, lions, dolphins and bats. However, cunnilingus-like behaviors, like the one shown in this spider are even rarer. Gregorič and coauthors suggest that oral sexual encounters could be a mechanism for boosting the male’s chances of paternity by either signaling the male’s quality or creating a chemical environment that would favor one male’s sperm against the sperm of rival males.

56 thoughts on “Weird: Scientists discover oral sexual encounters in spiders

  1. It’s your blog Anthony, do as you feel. I have learned something new today as I do every day here.

    • This aberration from normal arachnid behaviour is clearly due to CO2 poisoning and high temperatures. Give me a nice big grant and I’ll prove it! I already know how. Make an air tight terrarium, remove CO2 from the air in it, and reduce the temperature enough, and I am pretty sure that the spiders will stop doing this. /sarc

  2. Sounds interesting – trouble (for me) is that I now I initially doubt anything that science says or scientists have found. With so many calls to stand apart from other scientists and other research, my first thought is that it’s a push to be recognized or have a paper published or needed to gain funding.
    My problem, I know. At least they didn’t mention global warming anywhere (to my knowledge).

  3. One unmentioned advantage of the oral encounters is that the male likely ends up smelling a lot like the female. This could inhibit the cannibalistic meal that often follows mating.
    Male spiders that were able to survive mating because they smelled like honey-buns, and could then go on to mate several more times rather than once and then becoming a post-coital snack, would leave more offspring and thus be evolutionarily favored.
    One could check this by observing whether a male spider, once out of sight and grasp, spends time cleaning himself off, so that sweetie number 2 doesn’t detect sweetie number 1.

  4. It appears to be anything goes, so here goes.
    I have ( I guess) seen the mating ritual of Orb Weaver spiders.
    The male creates a swing that lets it touch the female only long enough to do what needs to be done, and not long enough to become her next meal.
    Take that for what it is worth 🙂

    • Don’t cha know? Nothing happened before “we humans started polluting the air with excess CO2” Kinky spider sex is just the beginning.

  5. This is attributable to male’s tactical method for getting his own sperm being used & not another of the female’s copulators. Insects use various strategies to get the female to put out sperm from previous male encounters. Look up “cryptic female choice” & will find decades of entomology investigations on how diverse the female insect tactics seem to be in many different (not all) kinds of bugs. So far appears no videos have been leaked on internet….

  6. Then there’s the bedbug. The males are so eager to mate that they can spear a female with their little spear in random places. The resulting sperm then migrate internally to the right place.

  7. “boosting the male’s chances of paternity”… or perhaps signalling that this is a mate and not something to be eaten?

    • As so often here I have learnt something new and had a good laugh as well.
      Thank you all.
      James Bull

  8. I think it’s highly likely that the male C. darwini performs cunnilingus on his mate so as to avoid being devoured after copulation by an unsatisfied female. Maybe more brutal but kinda like feminist female humans really ….

  9. Ridiculous to interpret this as “oral sex” ffs, for so many reasons.
    Humans are weird, especially many scientists, who lose touch with reality

    • Humans find it impossible not to attribute human-like terms and motives to animals, insects, etc. At one time, scientists seemed to try and avoid this, but those days are gone. Anthropomorphism is the new norm and if one argues with it…..

  10. Obviously this research wasn’t done out of pure scientific voyeuristic curiosity – wait for the grant proposal asking the government to print billions of dollars for the education of young spiders about the dangers of oral/sexual transmission of herpes. If you can’t make them stop, at least you can take the fun out of it and make them feel guilty and doomed.

    • FGM is an African problem not an Islamic one, the countries that have 95% rates of FGM are Christian countries not Islamic.

  11. vukcevic April 30, 2016 at 1:44 am
    Jeeezus Cristy, Vuc’s
    Will growing up I was the kid who drank a glass a milk before eating.
    Grew tall enough, but didn’t fill out much, (anywhere lol).
    Earned a nickname from an older sibling, the SPIDERWOMAN.
    So much for CIRs (corotating interaction regions).
    What I have read recently is that these current sheet crossings, are preceded by density enhancements. And
    seems that’s what I have been seeing in our cloud cover around here past couple days.
    SOLAR SECTOR BOUNDARY CROSSING (UPDATED): On April 29th or 30th, Earth will cross a fold in the heliospheric current sheet–a vast wavy structure in interplanetary space separating regions of opposite magnetic polarity. This is called a “solar sector boundary crossing,” and it could trigger geomagnetic activity around Earth’s poles. NOAA forecasters estimate a 40% chance of G1-class geomagnetic storms on April 29th.
    CHANCE OF STORMS THIS WEEKEND: NOAA forecasters estimate a 50% chance of G1-class geomagnetic storms on April 30th when a CIR (co-rotating interaction region) is expected to hit Earth’s magnetic field. CIRs are transition zones between fast- and slow-moving solar wind streams. They contain shock waves and density gradients that do a good job sparking auroras.

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