Sound production and hearing ability in the Hawaiian sergeant fish

Abstract

Sounds provide important signals for inter- and intraspecific communication in fishes, but few studies examine behavioral contexts of sound production and hearing ability within a single species. This study characterized the sounds and their behavioral contexts in a wild population of Hawaiian sergeant damselfishes (Abudefduf abdominalis), and compared their features to hearing sensitivity measured by both auditory-evoked potentials (AEP) and single-cell recordings in the auditory midbrain. The sergeant fish produces low intensity (∼85–115 dB rms re: 1 μPa), low-frequency (∼100–400 Hz) sounds during nest preparation, courtship an agonistic interactions. Both AEP and single-cell recordings show that fish are most sensitive to these frequencies (80–300 Hz) with best frequency at 100 Hz. However, auditory thresholds to tonal stimuli were approximately 20 dB lower for single-cell recordings than those measured by AEP experiments. Further, midbrain auditory neurons were on average more sensitive to playbacks of conspecific sounds than to pure tones. These experiments show that the hearing ability of this damselfish closely matches the intensity and spectral characteristics of sounds produced in the wild. Multidimensional studies that incorporate analyses of and responses to biologically relevant natural sounds are necessary to understand acoustic processing and the evolution of acoustic communication in fishes.