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Daring Jumping Spider - Phidippus audax
Spider Family: Salticidae
Live jumping spiders photographed in the wild at Winfield, Illinois, USA.
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Daring Jumping Spider, Phidippus audax
Jumping spiders have acute stereoscopic vision,
thanks to their large, forward-facing eyes. But
rather than moves the eye itself, as most
animals do, the jumping spder moves the retina
behind the eye. You can see the moveable retina
in the photograph above. The iridescent green
chelicerae are diagnostic of the genus
Phidippus in the jumping spider family,
Salticidae.
Jumping spiders do not build spider webs for
trapping prey - they use them for hiding and
laying eggs only. Prey is stalked and killed
much like a cat stalks a bird. A spider silk
lifeline is always at the ready; if threatened,
these guys rapidly lower themselves into the
underbrush. They also use the line to climb back
into postion should a jump go awry and they miss
their target. |
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Phidippus audax is
one of the most common jumping spiders in
North America. It is commonly called the
"bold" or "daring jumping spider." Most
casual photographers capture only this
species. The iridescent green
chelicerae (jaws with fangs, pronounced keh-lisseree) were a big
surprise when I got these pictures home and put them on the big
monitor - I had not noticed them while shooting. Now that I know
what to look for, I've learned this spider uses them as a threat
display; rapidly waving its
palpi (the little "feelers" underneath the face) in front of
them, creating a miniature light-show flashing green warning sign. I
would like to think this is the species that bit Peter Parker (aka
Spiderman). The more I see and study these
spiders, the more captivating and fascinating they become. It is
apparent others feel the same way; there is no dearth of information
on Salticids on the web. Here are some links explaining astounding
features of these creatures:
The Tree of Life Web Project has an excellent jumping off place.
There are articles, pictures and diagrams covering anatomy,
physiology, vision, even movies of them pouncing.
The Arachnology Homepage has an astounding array of
informational spider links. |
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A wary female watches me like a hawk.
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This large (10mm) female had taken up
hunting amongst the prickly pear cactus at
McAllister Park, San Antonio, Texas.
Jumping spiders are easily distinguished
from other spiders by their four big eyes on
the face and four smaller eyes on top of the
head. Around the world there are probably
more than 5000 species of jumping spiders.
Jumping spiders are charming lil buggers
that look up and watch you. Although a
jumping spider can jump more than fifty
times its body length, none of its legs has
enlarged muscles. The power for jumping
comes from a quick contraction of muscles in
the front part of the body increasing the
blood pressure, which causes the legs to
extend rapidly much as the hydraulics in a
low-rider car.
Their vision also allows communications by
visual means, such as the elaborate
courtship dances that males perform.
Salticids are perhaps as old and diverse as
mammals, though not many humans know their
world. Many salticids are colorful, they
take on a variety of body forms, and some
have disguises, looking like ants and other
organisms. The bright colors and elaborate
forms of some jumping spider species are
involved in courtship.
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