|Jumping Spider - Phidippus princeps|
Live female spider photographed at Winfield, Illinois.
Family Salticidae - Jumping Spiders
Spider Index | Spider Main | Orb Web | Cobweb
|This little gal in her retreat web was the first jumping spider I'd ever attempted to macro photograph. She was quite patient with me but steadfastly refused to come out and play.|
|A different time I had the same problem. Great fun though, and very photogenic.|
Jumping spiders have excellent vision, among the highest acuity in invertebrates. The eight eyes are grouped four on the face (the two big anterior median eyes in the middle, and two smaller anterior lateral eyes to the side), and four on top of the carapace. The two large, forward-facing eyes (AME) are tubular behind the lens, with a well-developed musculature, unique to salticids, that supports and moves the retina - the opposite arrangement of our own eyes. 
Spider musculature is also different from ours: in the spider, muscles operate from the inside to move external skeletal elements; our own skeletal muscles surround the elements they operate. But even these glaring differences are nothing compared to the jumping spider's brain and digestive system - their esophagus passes right through the brain, and one branch of the gut (analogous to our intestines) actually overlies the eyes and brain. 
|Jumping spider's anatomical points of interest:|
|Wondering how to get that bug identified? Please see the kind folks at Bugguide.net. (North America)|
North American Insects & Spiders is dedicated to macro photography of live, wild organisms in situ.
Class Arachnida / Order Araneae: Spiders are the largest group of arachnids. They are easily recognized by their eight legs, and there are few creatures great or small that elicit such irrational fear in mankind. The vast majority of spiders are completely harmless and offer beneficial services, chief of which is keeping the burgeoning insect population in check. I am continually amazed at the resourcefulness of these supremely successful predators. Spider Index | Spider Main