This week I came across an investigation with all the hallmarks of a cheap porno-violence paperback – including perverted sexual acts, cannibalism and self mutilation/castration during copulation. They main difference was that this was no fiction, it has actually been observed taking place on a regular basis between consenting adults. This unusual behaviour is the subject of a detailed investigation involving experts from both Hamburg and Finland.

The investigation focused on a rather unassuming local lady known to close associates as ‘Auntie Brunni’ (or Argiope bruennichi to use her full name). Brunni is an innocent looking arachnid who has two very strong character traits: the first is that she doesn’t like monogamy, and the second is that she generally cannibalises her male partners immediately after the act of sex.

Obviously these are not particularly pleasant attributes for a lady, especially when her male partners generally a) prefer monogamy (or limit themselves to a maximum of two mates if they are lucky enough to survive the first) and b) do not like to be ‘gobbled-up’ straight after sex.

In fact the male goes to considerable lengths to defend these preferences. On the one hand he will actually mutilate (in other words ‘castrate’) himself during the act of sex and use his severed sexual organ to ‘bung-up’ the sexual orifice of his female partner. This has has the effect of limiting her use of this orifice with other partners thereby encouraging a monogamous relationship. Clearly this is a noble sacrifice on the part of the male but would any chaps reading this article be prepared to go to these lengths to stop their partner going astray?

Actually these arachnids are not the only species in which males go to great lengths to ensure their partner stays monogamous. Male Frogfish (anglerfish) are known to bind closely to their partners after sex, some male frogfish actually suck out the females eggs for her or bind the eggs to themselves and carry them on behalf of the female. Some ants are known to block access to other potential mates after sex by leaving their abdomen behind, physically blocking the entry to their partner’s sexual orifice.

The male of this arachnid species has also developed another tactic to try and reduce the chances of his lady friend cannibalising him straight after sex. He terminates copulation early to try and make a quick exit from his lady’s tender embrace. If successful this tactic usually enables him to escape merely with the loss of a couple of legs. This means he must come away before fully completing his ejaculation in the hope that he will only be crippled (as well as having already castrated himself). This guy certainly takes monogamy seriously!

At the forefront of these investigations are Lutz Fromhage of the University of Jyväskylä in Finland and Jutta M. Schneider of the University of Hamburg.

They explain that the female spider has evolved to be promiscuous. Basically she ‘sleeps around’ and then selects the best performer to become the daddy of her offspring (once she has his sperm she has little need for him to continue living – hence eating him). This polygamous lady has sex with as many partners as possible and then chooses afterwards whose sperm she will use to fertilise her eggs. To support this promiscuity, and no doubt to counter her partner’s tendency to bung-up her sexual conduit with his organ, this female arachnid actually has evolved two orifices for sexual activity. In effect you could say this lady has two vaginas.

Not to be outdone, and also because he frequently sacrifices his sexual organ when he loses his virginity the male of the species also has two sex organs. Again to portray this situation in human terms – the gentleman has two penises.

The researchers have found evidence that the survival of this species of spider is improved by the female eating her (now redundant) male partner immediately after sex. They have demonstrated that the children of females who have eaten their partners are better nourished than those who have not benefited from this additional source of nutrients. So clearly the father does not die in vain but makes the ultimate sacrifice (after castrating himself) of offering his life so his children (and of course his partner) might prosper.

If you would like to read the original paper by Lutz Fromhage and Jutta Schneider in the Journal Ecology and Evolution you can find it by clicking on the link below:

A mate to die for? A model of conditional monogyny in cannibalistic spiders

You can also find out more about other research Jutta Schneider is doing at the University of Hamburg using the link here. (this page also has information about Dr Wanker’s research into Conflict Management among Parrots – which I hope to be able to review at a later date).

Chris Duggleby

If you are interested in reading my other health focused articles try the following

Torture In The Shower – Face and Body Soap Allergies – Main Suspect: Pears Transparent Soap

Poison in your Washing Machine: Allergic Contact Dermatitis from Laundry Detergents, Softeners, Conditioners and Whiteners

Is Alzheimer’s caused by the Gum Disease Bacterium P. Gingivalis – A Dementia Prevention/Treatment Breakthrough?

Toxic Chemicals in Sex Toys – 18 Vibrators, Cock Rings, Love Balls Tested – Only 3 Get All Clear

My T-shirt Made Me Sick – Textile Allergies – Sinusitis From Your Underwear