Hearing sensitivity in two black bass species using the auditory brainstem response approach

Recently, several bioacoustic studies have focused on the red eye bass (Micropterus coosae). One of these studies documented sound production, while the other played back sounds produced by prey items in order to determine their attractiveness to M. coosae. Surprisingly, the hearing ability of fishes in the genus Micropterus has received very little attention. The need for audiograms describing hearing in Micropterus is apparent. This study utilized the auditory brainstem response (ABR) approach to determine hearing sensitivity in terms of both sound pressure level (SPL) and particle acceleration in two black bass species, the red eye bass (M. coosae) and the Alabama bass (M. henshalli). Audiograms produced in this study expressed in both SPL and particle acceleration showed a positive relationship between hearing threshold and frequency. Micropterus coosae was most sensitive to frequencies that overlap with the peak frequencies of their vocalizations, and the vocalizations of a prey species, Cyprinella trichroistia. Bass hearing sensitivities at lower frequencies, measured in terms of particle acceleration, were similar to several sciaenid species.