Prey capture in the weakly electric fish Apteronotus albifrons: Sensory acquisition strategies and electrosensory consequences

Sensory systems are faced with the task of extracting behaviorally relevant information from complex sensory environments. In general, sensory acquisi tion involves two aspects: the control of peripheral sensory surfaces to im prove signal reception and the subsequent neural filtering of incoming sens ory signals to extract and enhance signals of interest. The electrosensory system of weakly electric fish provides a good model system for studying bo th these aspects of sensory acquisition. On the basis of infrared video rec ordings of black ghost knifefish (Apteronotus albifrons) feeding on small p rey (Daphnia magna) in the dark, me reconstruct three-dimensional movement trajectories of the fish and prey. We combine the reconstructed trajectory information with models of peripheral electric image formation and primary electrosensory afferent response dynamics to estimate the spatiotemporal pa tterns of transdermal potential change and afferent activation that occur d uring prey-capture behavior, We characterize the behavioral strategies used by the fish, with emphasis on the functional importance of the dorsal edge in prey capture behavior, and me analyze the electrosensory consequences. In particular, we find that the high-pass filter characteristics of P-type afferent response dynamics can serve as a predictive filter for estimating the future position of the prey as the electrosensory image moves across th e receptor array.