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Salticidaes Vision(jumping spiders). Group 1: Chingyee, Hilmi, Anthony. Overview . Eye Structure Colour Vision Survival Methods Summary. Eye Structure. Eye Structure.
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Salticidaes Vision(jumping spiders) Group 1: Chingyee, Hilmi, Anthony
Overview • Eye Structure • Colour Vision • Survival Methods • Summary
Eye Structure Trapezoid formed by anterior lateral eyes (ALE) and posterior eyes (PE) such that the shorter edge is posterior (dorsal view)
???? Jumping Spider Colour Vision
Colour Vision • Tetrachromacy • 4 colour cones • Sensitive from 300nm to 700nm • Layered retina • 4 layers • Outer 2 detect UV • Inner 2 detect green light
Experiment!! • Particularly sensitive to green (520-540nm) and UV (360nm) • Colour of light affected • Accuracy • Distance http://www.youtube.com/watch?v=0ZwTEcbX1Eg&feature=player_embedded
Defocusing for depth perception • Salticidaes (jumping spiders) gauge depth cues from the amount of defocus (comparing a blurry version of an image with a clear one)
Defocusing for depth perception • Taking into consideration the layers' respective distances from the lens of the eye, incoming green light is only focused on the deepest layer, while the other green-sensitive retinal layer receives defocused or fuzzy images • The fuzzy layer is proportional to the distance an object is to the lens of the eye.
Experiment!!! • ALE used in providing crucial warning to the spiders. • If the spider could detect the motion, it would respond by backing up rapidly, usually lifting up a couple of legs in a defensive posture • 3 groups of spiders (AME painted, ALE painted and no paint on the eyes)
Experiment!!! • The spiders were put into an enclosure with an iPod touch. On the screen was a black dot. • When the spider was looking toward the screen, the researchers pressed play, and the dot either • expanded quickly (as if it coming toward the spider) or • contracted (as if receding).
Summary • Labels of inner part of the eyes • The use of each eyes • Sensitive to green and UV • Layered retina • Defocus • Motion detection
Thank you for your attention!
Bibilo • http://jumpingspidersma.wordpress.com • http://wikis.evergreen.edu/m2o1112/index.php/Spiders_and_scorpions • http://www.earthtimes.org/scitech/green-light-jumping-spiders/1789/ • http://jeb.biologists.org/content/51/2/443.full.pdf • http://research.amnh.org/iz/blackrock2/families/salticidae.htm • http://salticidae.org/salticid/diagnost/general/eyes.htm