The extraordinary courtship dance of Australia’s peacock spider
SUMMARY: Meet the world's most adorable spider and watch his amazing courtship dance!
Adult male Maratus volans from Ku-ring-gai Chase National Park near Sydney. This male is displaying to a female he's spotted, with large extended and elevated opisthosomal fan, and extended legs III.
Image: Jürgen C. Otto and David E. Hill, 2011.
One of the most common phobias in the world is arachnophobia, the irrational fear of spiders. But there is one sort of spider out there that is so cute that even arachnophobes may like them.
I am talking about those diminutive jumping spiders (Family: Salticidae). Not only are these spiders very small, but they are generally colourful and they have keen eyesight -- essential for stalking and quickly jumping upon their prey since they do not spin webs to ensnare insects.
It's possible that I may be projecting just a wee bit, but jumping spiders seem to have personalities and, as one zoology professor told me when I was a grad student, they even learn to recognize their human care-givers.
But to my eyes, the most remarkable of all jumping spiders are those in the genus Maratus. Although only eight species have been formally described so far, at least 20 species are known, and all of them are found only in Australia.
Views of an adult male Maratus volans from the vicinity of Sydney, New South Wales, Australia. M. volans is little more than 4 mm in length, as shown here.
Image: David Hill, 2009.
The Maratus spiders are remarkable because the males of most of these species have colorful iridescent abdominal flaps that they expand during their courtship displays (Otto and Hill 2011).
"The first time I saw this mating display I was really blown away. I couldn't believe something like this would happen on this scale with this colour and movement", said Dr Jürgen Otto, an entomologist who researches marine mites at the Australian Institute of Marine Science in Townsville, Australia.
The drabber females of the species carefully study the males' brilliant colouring, vibrations and dancing movements to determine whether they are the correct species and to choose the healthiest one to mate with.
"They have very, very large front eyes. They just observe everything", remarked Dr Otto.
There's tremendous evolutionary pressure on these tiny spiders since unsuccessful mating attempts may end when the female makes a meal of her would-be paramour.
"If he's not doing the right thing, the female might think he's not the right partner", explained Dr Otto.
Anterior (1) and posterior (2) views of an adult male M. volans with expanded fan. The second view (2) suggests that ventral contraction of the elevated opisthosoma may be associated with inflation of the fan. This view also shows how flexibility at the articulation between the femur and the constricted proximal patella allows legs III to be raised into this extreme position.
Image: David Hill, 2009
These colourful fans may have other uses as well. Males of at least one species, M. vespertilio, also display these colourful flaps during ritualised contests (Otto and Hill 2012).
Dr Otto is quite fond of these spiders and his enthusiasm for them is making big contributions to our knowledge of these poorly known animals.
"The behaviour of this species does in a way remind me of a dog", he said.
"You can see how the spider gets excited. You can see when it gets frightened and wants to run away. You can see all these emotions that the spider has."
Thanks to Dr Otto's patience and diligence, the courtship dance of one species of peacock spider M. volans has been captured on film for the first time ever.
"When I came down to Sydney, I was a bit bored because there weren't that many things to photograph", explained Dr Otto, who is an avid amateur photographer.
"But since I found this species here, I just don't want to live anywhere else. I think it's probably the most beautiful spider in the world."
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Otto J.C. & Hill D.E. (2011). An illustrated review of the known peacock spiders of the genus Maratus from Australia, with description of a new species (Araneae: Salticidae: Euophryinae). Peckhamia, 96 (1) 1-27. free PDF
Hill D.E. (2009). Euophryine jumping spiders that extend their third legs during courtship (Araneae: Salticidae: Euophryinae: Maratus, Saitis). Peckhamia, 74 (1) 1-27. free PDF
Otto J.C. & Hill D.E. (2012). Contests between male Maratus vespertilio (Simon 1901) (Araneae: Salticidae). Peckhamia, 98 (1) 1-17. free PDF
Jurgen Otto's quotes came from this video interview.
Jürgen Otto's photostream of several peacock spider species.
NOTE: This piece was slightly edited from the original, which was published on the Guardian.
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