Simon Fraser University

Spatial discrimination with a very simple eye

A. H. Jay Burr

Emeritus, Department of Biosciences, SFU
Monday, October 19 at 3:30 PM in P8445.2



How can a simple eye provide spatial information about the animal’s environment? Of the five simple eye types found in the phylum Nematoda, one occurs as a single eye at the anterior tip of the worm and consists of  a cornea, two photoreceptors and a pigment cup. It is used by the female of this grasshopper parasite to guide her to egg-laying sites in upper vegetation, where grasshoppers feed. I will consider the optics of this eye in the context of a discovered scanning motion of the worm’s anterior, and describe experiments that support a simple mechanism for spatial discrimination of light sources. The results also raise the question of what is the simplest organ that could be called an eye.