| Affiliation: | Laboratory of Fishing Production System, Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido 041-8611,;National Research Institute of Fisheries Engineering, Kamisu, Ibaraki 314-0421,;Field Science Center for the Northern Biosphere, Hokkaido University, Hakodate, Hokkaido 041-8611, Japan |
| Abstract: | ABSTRACT: The auditory brainstem response (ABR) of fishes is commonly measured by bringing the heads of the fishes out of the water in a small tank. However, this method is inapplicable to experiments for large fishes that are economically important in large spaces such as the sea or in a large tank. This paper describes a method of recording, the ABR for fishes in water, without exposing the fish heads to air, by using a waterproof, insulated electrode. To evaluate the effectiveness of this method, the goldfish Carassius auratus was investigated, and the ABR waveform and auditory thresholds measured in water were compared with those measured on the surface. Both ABR waveforms and auditory thresholds showed similar trends between the two methods. The underwater ABR method is useful to measure the auditory thresholds of larger fish in natural or on-site environments such as the sea, net enclosures and large aquaria in which precise positioning of the fish is not possible. However, more improvement is needed to apply this method to large fishes. |
