Hearing in eight species of northern Canadian freshwater fishes

The hearing thresholds of eight fish species from northern Canada were measured using auditory evoked potential techniques. The species with the best hearing was the lake chub Couesius plumbeus , followed by the longnose sucker Catastomus catastomus , both which had relatively sensitive hearing over the frequency range tested from 100 to 1600 Hz. The remaining species (troutperch Percopsis omiscomaycus , nine-spined stickleback Pungitius pungitius , pike Esox lucius , spoonhead sculpin Cottus ricei , burbot Lota lota and broad whitefish Coregonus nasus ) all showed most sensitivity to low frequencies (<400 Hz) and had relatively insensitive high frequency hearing. The two species with the best hearing are otophysan fishes with connections between the swimbladder and inner ear. The spoonhead sculpin lacks a swimbladder, while the other non-otophysan species have swimbladders, but no specialized connection to the inner ear. These results can be used to predict the potential impact of anthropogenic noise, such as seismic air gun blasts, on hearing in these species. The species with the most sensitive hearing (lake chub and longnose sucker) are most likely to be affected by activities such as seismic air gun surveys.