The Peacock Spider

Spiders from the genus Maratus, in the family of Salticidae (jumping spider), are also known as the Peacock spiders. The reason they are called like this is because of their flashy colored butts, which they proudly use to impress the females. These spiders grow to a length of between 4 and 5 mm. The females and young spiders tend to be a dullish brown, but when the males mature they develop an impressively colored pattern. You can find these peacock arachnids in Australia, specifically Queensland, New South Wales, Australian Capital Territory, Western Australia and Tasmania.

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The male (right) and female (left) Maratus volans.

Miniature brawlers

They might be tiny, but they are feisty.Jumping spiders don’t build webs, so they find other ways to capture their prey. The peacock spiders have developed superior eyesight, which allows them to see in detail, color, and a multitude of distances. Combine this with the ability to jump 20 times the length of its own body and you have the perfect stalker. They lull their prey, usually crickets or other spiders, into a fall sense of security and pounce on them.

Besides using their fighting skills to take down prey they fight a lot amongst themselves. The males all want to have a shot at impressing a female. To decide who can have a go at it, they scrap it out.

The mating ritual

When the male finally gets the chance to impress the female the first attempt to impress is by waving around his legs. Their technique has some resemblance to the flag semaphore often used by the US Navy.

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Semaphores of the Peacock spider

If the female accepts this initial approach the male spider can bring out its secret weapon. He raises the two flaps wrapped around his abdomen and stuns the female spider with vibrant colors. The male adds to the show by dancing back and forth.

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The peacock spider’s dance

Hopefully for the male spider the female is amazed by his display. Otherwise she might be inclined to make him a meal. Bad dancers get eaten! If she does like him she can do her own dance where she turns around and does a seductive dance with her abdomen.

Another amazing fact about the peacock spider is that the 44 species that exist of this spider all have their original choreography and unique colors. They are such a colorful bunch!

Courtship in action

How are they so colorful?

A group of Dutch, Swiss, and Australian scientists were asking the same question. They investigated the flaps wrapped around the abdomen of the spider and found that they were covered by richly colored scales. These scales are formed by modifying the hairs on the abdomen of the spider. The white, cream and red scales have elaborate shapes with multiple spines, and are pigmentary. The blue scales do not have pigments, but instead get their color from the specific nanostructure. Two chitinous layers with ridges, with in between an array of filaments form an intricate system of light manipulation. In Figure 1 the scales can be seen in more detail.

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Figure 1. Color of the male peacock spider Maratus splendens. (a) Courting male. (b) The central part of the opisthosoma with mainly pigmented scales, coloured red, orange and cream-yellow. (c) At other locations blue or purple scales occur. (d) The blue scales are distinctly convex. (e) The cuticle consists of convex, blue coloured cells. Scale bars, (a) 2 mm; (b–d) 100 µm; (e) 50 µm. - Doekele et al.

Thanks to @trumpman for reminding my brain that these dancing spiders exist. This post would probably not be here without him. If you would like more videos about these stunning arachnids go to Peacockspiderman’s Youtube channel. For beautiful pictures check out Jurgen Otto’s Flickr.