The Mimicry of Spiders

"QUANTUM SHOT" #495
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Text written by Atila, a Brazilian biologist who writes about biology and evolution to Rainha Vermelha and manages Lablogatórios, a Portuguese language science blogs community.

All dressed up for dinner.

Before we discuss the fantastic mimicry (camouflage and adaptation) that some spiders employ for hunting and waiting for prey, let's have a look at how spectacular (and notably cute) these creatures can get. Here, for example, is the "Snow White":

Salticidae (or "Jumping Spider") is a true hunter among spider family. Instead of building a web and sitting on it, these spiders hunt actively relying on their exceptional vision. Such highly developed visual sense and fantastic eye arrangement play a significant role, when females choose males.

Not to be outdone, the males, too, have very colorful displays and well-ritualized mating techniques, as you can see on the next pictures (courtesy Opo Terser):

"What are you looking at?" -

The colors are wonderful: blue, red formal wear... "A Bluebeard"? -

This guy looks particularly wise with his white beard:

Look into these headlights...

Every one has it's own expression... This is a little coy:

Zebra stripes and orange pom-poms (Maevia inclemens):

Athletic fit:

Old and wise:

I Can Has Cheezburger? -

Jabba the Hutt (actually, the vary large wolf spider - Hogna species) -

(all above images courtesy Opo Terser)

Awww!..

(image credit: Hannes Mitchell)

Hilarious jumping spider mating behavior:

"A male jumping spider trying very hard to excite a female jumping spider. That thing it does...with it's front legs... He taps, he scrapes, he turns and twists...he stops!... Make sure you turn up the volume on your speakers...the sounds are half the act"

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Sensational Mimicry Acts!

Some salticidae have evolved to mimic ants. By doing so, they can avoid predators and ant attacks - this is a big threat to these small forager hunters. They form the Myrmarachne genus. As ants have 6 legs ant 2 antennae, these spiders keep the front legs over the head imitating the antennae. What they can't hide is the number of eyes, look to the head and you will see two big eyes like ants and in the front of the head four or six more eyes.

These are all spiders; not the 8-eyed ants!

(image credit: Opo Terser)

(images credit: Hannes Mitchell)

Very long jaw - Males usually have elongated chelicerae which they use to fight off rivals. These chelicerae may be as long as half their body length:

(image credit: Hannes Mitchell)

More black-ant-like spiders:

(images credit: Malaysian Spiders)

Other spiders (not necessarily jumping spiders) may use different mimicry. Some, like crab spiders, may blend with flowers and wait for insects... Do you see the hiding "Yellow Death"? -