Fish vision and sexual communication
 in the kelp forest

Molly Cummings, Ph.D.
University of Texas

Wednesday, December 4, 2002
3:00 p.m. – Pacific Forum

Variation in the environment is considered to be 
a major force in 
the evolutionary diversification of animal sensory systems and communication traits. As species diverge in habitat use, sensory systems are predicted to diverge to meet target detection needs. Interspecific variation in sensory sensitivities is predicted to result in sensory biases that should predict the direction of communication trait (e.g. courtship signal) evolution across species. I test these predictions with a group of closely related fishes (surfperch: Embiotocidae) living in the California kelp forest, by incorporating measurements of species-specific optical habitat use, photoreceptor absorbances, target reflectances, and fish behavior into a visual detection model. The results indicate that: (1) Surfperch sensory systems covary with microhabitat use. (2) Divergence in visual pigment absorbances results in luminance or chromatic detection biases. (3) Surfperch courtship traits, both physical (color patterns) and behavioral (display), match the diverging biases of their sensory systems.