For the identification of insects and other fauna and flora of South Africa.

Friday, July 16, 2010

Better than "Sex in the city" - spider courtship

Although this information is not new too me, I thought it was well written and wanted to share it with you. The extract is from Filmer’s Spiders.

“When it comes to reproduction, most people would say ‘I’m glad I’m not a spider. Spiders have earned a reputation for cannibalism following mating, and arachnid reproduction can indeed be dangerous for the male, and is also highly complex – both in the courtship phase and in the actual mating process.

Unique to spiders is the modification of the male pedipalps (feelers) as organs of reproduction. As remarkable is the fact that the female epigynum(genital organs) is so constructed as to accept only the configuration of her conspecific male’s pedipalp. This ‘lock-and-key’ mechanism ensures that there can be no species mixing. (Spider taxonomists rely almost entirely on the shape and configuration of the sexual organs to identify different species.)

Immature spiders are, for all practical purposes, sexless. In immature males, the pedipalps are nonfunctional, as is the epigynum in immature females. These develop into functional reproductive organs at the time the final ecdysis (shedding of the hard exoskeleton) into adulthood. Once fully mature, the male’s single aim in life is to find a female with which to mate.

Before courtship begins, the male’s pedipulps have to be charged with seminal fluid, in both males and females, the genital pore is situated on the ventral (under) side of the abdomen, between the book lungs. To transfer sperm from this pore to the pulps, the male spider first spins a sperm web (a small, triangular or square web) just above the substrata. Straddling the web, he deposits a drop of sperm at its centre. The spider then either dips his palps into the sperm or presses his palps up against the sperm from the underside of the web. Similar to an old-fashioned fountain pen, the embolus (the sex organ situated at the end of the pedipalp) draws up the fluid.
The female spider lives a solitary life devoted to catching prey and feeding. Whatever moves in her vicinity, she will attack and either kill or drive off. As a result, the male spiders have evolved a complex and amazing variety of courtship rituals, only a few of which is described here. There are two main approaches, and these are based on the visual ability of the particular species. Long-sighted spiders are mainly diurnal (daytime) maters, while short-sighted ones will mate at any time.

Once a female has been located, it is up to the male to convince her that he is a male of her species and that she should succumb to his advances. In the families Lycosidae and Salticidae, which have good vision, the males carry out and elaborate courtship dance. The lycosid male waves his pedipalps up and down in rhythmic movements while tapping the front pair of legs on the substrata. He moves slowly towards the female, awaiting a signal that she is ready to accept him and that she will not attack. There may be some leg touching and rubbing before actual mating takes place. Some salticid males are adorned with elaborate hairs – often brightly coloured – on their palps. Waving these, with the first pair of front legs raised high above his head, the spider moves in an arc around the female, waiting for her signal of acceptance. On the other hand, those spiders with poor vision do not have and elaborate courtship dance and may indulge in no more than some leg tickling before mating occurs.

For most web-building spiders, courtship is purely a tactile affair, with the male coming to the edge of the web and plucking or tapping on the silken strands to announce his presence. Some araneid males are much smaller than their mates and in Argiope the female can weigh up to a thousand times as much as the male. Obviously the Argiope male has to be extra careful to avoid becoming a meal!! In some of the larger araneid species, the male approaches the female’s web and tweaks the strand on which she is sitting. Invariably, he has to drop down on a drag line to avoid her initial rush forwards to attack, before clambering back up to the web and trying again …… and again and again and again!
Once the female is convinced that her suitor is a prospective mate and not prey, the male spins a special mating thread. He proceeds to lure the female onto this thread with more plucking and tweaking movements. Female araneid ardour is not long-lasting and once mating has occurred, the male has to beat a fast retreat or suffer being eaten. (Many spider genera do have much less complex and far more civilized mating procedures, however.)

The males of some spider families (for example the theridiids and linphids) are equipped with a stridalatory organ. Once on the female’s web, the male spider may stridulate, which causes a high-pitched vibration. The sound not only brings the female out into the open, but renders her receptive to the male’s approach.

The act of copulation can last from seconds to hours, depending on the species. In some, the courtship is greatly extended and the mating brief, while in others there may be hardly any courtship, while mating may last up to seven hours. The male inserts his pedipalps one at a time (or in the case of some more primitive spiders, both at once) into the female’s epigynum and thus transfers the sperm to her.

The most notorious spouse-eating spider is Latrodectus whose antisocial behaviour has earned it the common name “Black Widow Spider”.

There are some rather amusing mthods that male spiders use to avoid falling prey to their prospective mates. The male of some of the pisaurid species catches a fly and neatly enswathe it in silk, then, holding the wrapped gift in his chelicerae (mouth), he approaches the female. Once she has accepted it and has started eating it, he nips around and proceeds to mate with her. The males of some of the crab spiders are tiny in comparison to their mates. To overcome his size disadvantage, the male casts strands of silk to and fro across the female’s abdomen while she is laying in wait for prey, tying her down like the Lilliputians tied down Gulliver. Once she is secured in this way, he mates with her and then leaves her to her own devices. She may take several hours to extricate herself.”
My question now is "How much human behaviour do you see in the above?"

32 comments:

Philip said...

This sounds like to much hard work for me LoL! Can you imagine if Female Humans were like this there would be no Males on the Planet Maybe that would be a good thing :))
talk about spinning her a web.Nope maybe spin a story LoL!

Tony nile life said...

Well madam you surely suprised me.
bondage and all that,
not so canabalistic as the female mantis though. or do they eat the mate after,

Philip said...

And another thing these females are much larger than the Males in comparison, Human ladies would be the size of a Volkswagen Beatles oh dear that sounds hectic !!

Unknown said...

Great information, super shots and, last but not least, very cool title! :-)

Gaelyn said...

Sounds very complex. Sure glad I'm not a spider.

Rusty said...

An interesting exception is the (common name) Zebra jumping spider. I don't know if you have any of them in your part of the world though. They also have a complex mating ritual consisting of what would be called semaphore signals. (They are not web weavers). The male often stays around to build the nest where the young will hatch - and sometimes help 'rase' them. A facinating study. ATB!

Craver Vii said...

Fascinating! The intricacies and complexities of life are rewards for those who put the effort into proper observation.

SAPhotographs (Joan) said...

LOL!! I was comparing this to humans too Philip and came to some conclusion which I cannot repeat here. :) All I can say is that I like how female spiders operate. LOL!! Now read into that what you will!! :)

SAPhotographs (Joan) said...

LOL!! Looks like this post is going to get me into a LOT of trouble if I say what I think Tony. :)

Imagine the conversation between the female spider and her offspring when she tells them the food she has provided is actually their father!! LOL!! THAT could prove to be interesting so it is a good thing they dont talk to each other. :)

Yes, the female mantis does eat the males too after they have mated.

SAPhotographs (Joan) said...

This is going from bad to worse Philip. LOL!! If human females were as big as the VW, I would hate to think of the population right now, we would have become extinct far quicker than dinosaurs!! :)

SAPhotographs (Joan) said...

The title came to mind as I was typing the article Jose though I never saw the TV series, only heard about it. :)

SAPhotographs (Joan) said...

I think the female has a lot going for her Gaelyn. Someone asked me the other day if I was a spider. LOL!!

SAPhotographs (Joan) said...

Wonderful to have you visit again Rusty. :)

We have one which might be called a Zebra jumping spider as it has the black and white stripe pattern but a lot of our spiders do not have common names. That is interesting behavour and not very common. ATB2 and please visit more often. :)

SAPhotographs (Joan) said...

It seems like it Craver. I found the whole thing to be fascinating and see so much human behavour in it. Okay, I will admit it is not often we make a meal of our partners though. LOL!!

S said...

WOW - this is so amazing! If we learn these things at school, surely no one would bunk. My conclusion after your post: females are a difficult species! LOL! Enjoy your weekend :)

Diane said...

What a complicated sex life. I am also glad I am not a spider:) Diane

This Is My Blog - fishing guy said...

Joan: Is this a similar ritual where you take the woman to dinner if you want to get lucky?

Becky said...

I'm sure no man in his right mind would ever go through all this. LOL
Great info and awesome pictures Joan.
B.

blog with no name said...

Hi Loan!
Reproduction in humans can be every bit as treacherous! FFirst there is the engagement ring... A second job trying to pay for it... Then the wedding bills... The mortgage payments... College savings accounts... Divorce lawyers... Alimony... Then finally on your 50th birthday your heart explodes into shreds and the ex gets everything including the life insurance check...
Sure am glad my sweetie's not a Black Widow LOL! Although for some men, it might be a long awaited gift to be devoured quickly! LOL!

Great post! And even greater pictures! Have fun with your new endeavor!

Rambling Woods said...

Wow..this is fascinating...I will have to get a book on spiders. I was thinking today in between almost getting bitten by a snapping turtle and rescuing an injured goose that all of nature is about sex and we aren't so different from animals...

SAPhotographs (Joan) said...

LOL!! You are much too young to come to that conclusion Sreddy. :) Read "Blog with no name" comment from Mike and you might get an idea what he thinks of the whole idea. LOL!!

We (woman) are wonderful and soft and sweet - well okay, most of us and not all. :)

SAPhotographs (Joan) said...

I like some of the aspects of being a spider Diane. I have always wanted someone to rub legs with. LOL!!

SAPhotographs (Joan) said...

LOL!! Something like that Tom but in this case, after he has been lucky, he IS the meal. LOL!! A slight reversal. :)

SAPhotographs (Joan) said...

Thanks Becky. Don't you think that men have to go through almost the same thing with having to wine and dine us first, not to mention the chocolates and flowers? Us ladies are not easy to win over you know. LOL!!

SAPhotographs (Joan) said...

LOL!! That sounds almost as if the men would welcome being eaten if they have to go throught all of that Mike? LOL!! What a way to live!! The only difference I see here is that in your senario, at least she feeds him on a regular basis. :)

Yes, you are lucky you landed up with such a wonderful sweetie.

Dont worry about the typing error, I do it all the time. :)

SAPhotographs (Joan) said...

No, we are just a different species Michelle. Remember, we are also mammals. :)

Sounds like you are having a fun day. :)

Zane said...

To mate and then be eaten alive - what silly male would make such an error - oh wait these are spiders - there brains are tiny.

Fantastic article Joan!

SAPhotographs (Joan) said...

LOL!! You almost made a mistake there Zane. :)

Thanks.

JRandSue said...

Stunning shots,well done.

SAPhotographs (Joan) said...

Thanks John and Sue. I am always pleased when the pics come out so well.

myonlyphoto said...

Oh wow Joan this is amazing. And you know what's amazing someone actually study this, that must have been a life time research. But most of all I am stunned by your macro images, they are stunning. Anna :)

SAPhotographs (Joan) said...

Thank you for your kind words Anna. All of the insect world is so interesting and if I had the money, I would go and study them too as it is fascinating. :)