Sunday, February 22, 2015

Dear Abby

By Jason Kent

Dear Abby: I am what I believe to be a perfectly average female. My legs are nothing special, but they are long and there are 8 of them, so I often catch males staring. I also have a sexy, hourglass-shaped red mark on the underside that the men say is to die for. However, that’s the problem. Whenever I take a man back to my web for sexy times, he ends up killing himself. Now I don’t know if I should be flattered that I am the last thing the men want to do in their life, or if something is wrong with me? Abby, please help! 
-RacyRedBackside7
Female Australian Redback Spider
Dear RacyRedBackside7: There is nothing wrong with you! At least you don’t have to figure out the logistics of the awkward next morning. Do you kick him out as soon as he’s done, do you get up early and leave for work while he’s still sleeping and leave a note saying “Feel free to grab the coffee and bagel on the counter on your way out”, or do you have breakfast together and pretend you had fun and that you’ll totally do this again sometime. Nope! Most ladies would consider you lucky!
 Anyways, to actually answer your question, for Latrodectus hasseltii, an Australian Redback spider like yourself, your situation is actually very common. As it turns out, 65% of males of your species will sacrifice themselves during intercourse by somersaulting onto their mates fangs (Kaston, 1970). In addition, (and something you may have also experienced but were too embarrassed to bring up) the males are typically consumed while in this position (Andrande, 2003). Below you can see an image of this taking place. I would have linked to a video, but when I was trying to find one, I thought I felt something crawling on me and almost threw my laptop so a picture it is! 
Now the real question is why do they do this? Believe it or not, the answer isn’t because the sex is so bad they can’t bear to continue any longer. In fact, it is actually the opposite. By feeding themselves to their mate, the males actually prolong copulation which increases likelihood of fertilization (Forster, 1992). A study by Andrade showed that more than 80% of Redback males die before they ever find a potential mate. Additionally, most males become functionally sterile after mating, and repeated male mating does not increase the probability of successful fertilization (Andrade and Banta, 2002).
 From a biological standpoint, it makes sense. Put yourself in the 8 shoes of a guy; you find yourself in the company of a perfectly average woman. You’re already luckier than 80% of your fellow males. You know the chances of finding another female are extremely slim, and even if you do you’ll be firing blanks. You might as well do everything you can to increase the chance of producing offspring. To them, even if it means being eaten by the woman you are having sex with, the extra few moments they get to have sex is worth it.
So no, there is nothing wrong with you. However, you also shouldn’t be flattered and let it get to your head. Statistically speaking, you are your mates’ only option. They are just doing what they need to, to pass on their genes to the next generation. Remember that the next time you decide to have a snack in bed.

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Dear Abby: I have a bit of an embarrassing problem. I seem to stand out from the other horses in a weird way. I’m the only one who is ever horny. I wake up and I’m horny. Lunch time? I’m horny. Time to go to sleep? You guessed it. I’m still horny. Why am I so different from the other horses?
-Pegasus4

Dear Pegasus4: You’re actually not a horse. You’re a unicorn. No science needed here. Can’t change who you are. You were born this way.
A horny unicorn.
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Dear Abby: I am pretty sure my girlfriend is faking her orgasms. I try to time it perfectly so that I release my sperm as she releases her eggs, but we haven’t had successful fertilization. Last time I tried looking to see if anything strange happened and I’m pretty sure she didn’t even release her eggs! What gives?
-Bigbrowntrout

               Dear Bigbrowntrout: First of all congratulations on your decision to have babies and finding a willing partner! As you mentioned, your species, Salmo trutta, have oviparous reproductive systems, in which both eggs and sperm are released during spawning and then covered in gravel as seen below. However, what you might not know is that females can only spawn up to eight times before depositing all of her eggs (Petersson and Jarvi, 2001). This means females must be very careful when and with whom they spawn to ensure the best chance of fit offspring.

Female brown trout spawning with male behind
Female brown trout spawning with male behind
               This leads to a few possible reasons why your mate and other female brown trouts would fake orgasm. The first has to do with logistics. First, in order for successful fertilization, the male must be properly aligned behind the female while spawning. If the male is oriented wrong, the female may have a false orgasm triggering the male to release his sperm (Petersson and Jarvi, 2001). This is because the cost of females to release eggs is much higher than that of males releasing sperm so it is better for the male to make the mistake.
               Another likely scenario is that it is a tactic for her to maintain control over her mates. Often times in oviparous species, subordinate male fish will swim behind the spawning pair and swoop in right when the female orgasms, releasing his own sperm in an attempt at fertilizing the females recently released eggs (Perersson and Jarvi, 2001). For a dominant male such as yourself, this competition would reduce your reproductive success.
               While her faking an orgasm results in you being unable to fertelize her eggs and causes you to start reevalutating everything you’ve ever done that lead you to that point, it’s actually for the best. Unlike for her, releasing your gametes is not very costly. She only has so many eggs and you want to make sure you get it right knowing you are the only possible father. Trust her to know when the time is right, and when it is, she won’t fake it.




References
Kaston, B.J. 1970. Comparative biology of American black widow spiders. Tansactions of the San Diego Society of Natural History 16: 33-82.
Andrade, M.C.B. 2003. Risky mate search and male self-sacrifice in redback spiders. Behavioral Ecology 14: 531-538.
Forster, L.M. 1992. The stereotyped behavior of sexual cannibalism in Latrodectus hasseltii Thorell (Araneae: Theridiidae), the Australian redback spider. Australian Journal of Zoology 40:1-11.

Andrade, M.C.B. and E.M. Banta. 2002. Value of male remating and functional sterility in redback spiders. Animal Behaviour 63: 857-870.
Petersson, E. and T. Jarvi. 2001. 'False orgasm' in female brown trout: trick or treat? Animal Behavior 61: 497-501.

Photo Credits
http://www.outback-australia-travel-secrets.com/image-files/australian-spiders-redback2.jpg
http://cdn.phys.org/newman/gfx/news/2006/female_spider_eating_male.jpg
https://www.teepublic.com/show/40056-im-so-horny
http://www.arkive.org/brown-trout/salmo-trutta-fario/image-A9859.html

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