Modeling an electrosensory landscape: behavioral and morphological optimization in elasmobranch prey capture.

Most biological sensory systems benefit from multiple sensors. Elasmobranchs (sharks, skates and rays) possess an array of electroreceptive organs that facilitate prey location, mate location and navigation. Here, the perceived electrosensory landscape for an elasmobranch approaching prey is mathematically modeled. The voltages that develop simultaneously in dozens of separate sensing organs are calculated using electrodynamics. These voltages lead directly to firing rate modifications in the primary afferent nerves. The canals connecting the sense organs to an elasmobranch's surface exhibit great variation of location and orientation. Here, the voltages arising in the sense organs are found to depend strongly on the geometrical distribution of the corresponding canals. Two applications for the modeling technique are explored: an analysis of observed elasmobranch prey-capture behavior and an analysis of morphological optimization. For the former, results in specific predator-prey scenarios are compared with behavioral observations, supporting the approach algorithm suggested by A. Kalmijn. For the latter, electrosensory performance is contrasted for two geometrical models of multiple sense organs, a rounded head and a hammer-shaped head.