small, smart and fast
I have never seen a faster or smaller spider. This individual is only 4mm wide (the size of the opening of a soda straw), motionless for the moment, on a paper towel. Was surprised to learn that spiders are not insects, though both are arthropods. Unlike insects, spiders do not have antennae. Spiders have the most centralized nervous systems of all arthropods and unlike most other arthropods, have no extensor muscles in their legs -they extend them by hydraulic pressure. I haven't seen any webs in the area and believe this one hunts and runs down its prey. According to Wikipedia, hunters of the genus Portia show signs of intelligence in their choice of tactics and ability to develop new ones.
It seemed like this spider was as curious about me as I was about it. We were perfectly content to stare at each other. If I tapped my finger nearby though, it would run away, but then come back after a minute or so to continue observing. It could run about 2/10 meter (8 inches) in a second. That's 50 body-lengths a second. If this spider were the size of a 4m-long automobile, it's speed would be 200m/sec = 12,000m/min = 720,000m/hr = 720 km/h or 447 miles per hour
Original photo from which this image was cropped:
www.flickr.com/photos/9482738@N07/28410156403
small, smart and fast
I have never seen a faster or smaller spider. This individual is only 4mm wide (the size of the opening of a soda straw), motionless for the moment, on a paper towel. Was surprised to learn that spiders are not insects, though both are arthropods. Unlike insects, spiders do not have antennae. Spiders have the most centralized nervous systems of all arthropods and unlike most other arthropods, have no extensor muscles in their legs -they extend them by hydraulic pressure. I haven't seen any webs in the area and believe this one hunts and runs down its prey. According to Wikipedia, hunters of the genus Portia show signs of intelligence in their choice of tactics and ability to develop new ones.
It seemed like this spider was as curious about me as I was about it. We were perfectly content to stare at each other. If I tapped my finger nearby though, it would run away, but then come back after a minute or so to continue observing. It could run about 2/10 meter (8 inches) in a second. That's 50 body-lengths a second. If this spider were the size of a 4m-long automobile, it's speed would be 200m/sec = 12,000m/min = 720,000m/hr = 720 km/h or 447 miles per hour
Original photo from which this image was cropped:
www.flickr.com/photos/9482738@N07/28410156403