Abstract
A series of experiments was undertaken to investigate methods of sound source localization by fish. In these experiments, positive phonotaxic responses of gravid female plainfin midshipman fish (Porichthys notatus) to low-frequency, playback tones (80–90 Hz) were studied as they approached sound sources. The sound fields for simple (monopole) and relatively complex (dipole) sources within the behavioral arena were measured and characterized in terms of pressure and particle motion. Results indicate that female midshipman fish are able to locate sound sources in the near field using acoustic cues alone, and that they used the particle motion vectors to locate the source in both the monopole and dipole sound fields. It was also found that neither the lateral line nor the swim bladder was necessary for localization behavior, and that the fish were able to solve the 180 deg ambiguity inherent in the particle motion vectors. [Work was supported by the National Science Foundation.]