This research will investigate sound source localization by fishes to ascertain how fish integrate the various sound cues available to them to behave appropriately in complex acoustic environments. Evidence suggests that the capacity for sound source localization is common to mammals, amphibians, birds and reptiles, but surprisingly it is not known whether fishes locate sound sources in the same manner. Therefore, sound source localization by fishes remains an important topic in biology and in the hearing sciences. This study will test the major assumptions of several related theories, including the leading theory of sound source localization by fishes. The plainfin midshipman fish (Porichthys notatus), in which females locate males by sounds that the males produce, will be used as a general model to investigate how fishes localize underwater sound sources. Two hypotheses will be tested: 1) fish orient to the direction of acoustic particle motion to localize sound sources (a major assumption of several, related theories including the leading theory of sound source localization), and 2) both particle motion and sound pressure detection (via the swimbladder) are necessary for sound source localization, but neither alone is sufficient. As an integral part of this research program, both graduate and undergraduate students will receive training and mentoring. In addition, annual public lectures regarding this research will be presented at the University of California Bodega Marine Laboratory.
