Spiders No.24 – A Crab Spiders Eye Complex

Walter Piorkowski · Post by **Walter Piorkowski** » Fri Dec 31, 2010 7:11 pm

Leitz Ortholux microscope
4X Leitz projection eyepiece plus 1/3x relay lens

Image No.1
61 images at 5 micron increments
Olympus 10x Achromat objective
Diffused Fiber Optic Illumination

Image No.2
25 images at .001 inch increments
Leitz UO 6.5 X Achromat ULTROPAK objective
Diffused Fiber Optic Illumination

Canon 50D
Zerene and Photoshop processing.

This colorful crab spider is one of the flower-inhabiting members of the family Thomisidae. Six of the eight eyes are seen roughly straight on while the two remaining members are only seen by their lenses. The eyes are on what arachnologists call prominent pale tubercles.

Walt

Mitch640 · Post by **Mitch640** » Sat Jan 01, 2011 2:54 am

I wonder how well they can actually see out of that setup? Are the red eyes actually different kinds of eye?

Walter Piorkowski · Post by **Walter Piorkowski** » Sat Jan 01, 2011 1:34 pm

Can't say if the red eyes are differant Mitch, but I know from personal experience that these animals have keen eyesight and strike quickly and accuratly from their hiding spots.
Walt

Charles Krebs · Post by **Charles Krebs** » Sat Jan 01, 2011 2:05 pm

Walt,

Can't say if the red eyes are different

I can't say either, but I have noticed something when photographing these "in the field".

Here's a part of something I once posted:
Those two eyes were interesting. No flash was used. While taking the photos it was apparent that the spider could "rotate" or ""move" something under the surface that made the eye appear either red, black, or partially red/black when viewed from the same position.

Walter Piorkowski · Post by **Walter Piorkowski** » Sat Jan 01, 2011 7:44 pm

That is very interesting Charles. I have to admit that my observations of them in the field were not that closeup. I will have to increase my magnification.
Walt