长江鲟幼鱼的听觉阈值研究

THRESHOLD OF THE JUVENILE ACIPENSER DABRYANUS DUMERIL

试验采用室内噪声控制的方式模拟野外自然噪声环境,以长江鲟(Acipenser dabryanus Dumeril)幼鱼为实验对象,使用TDT听觉测试系统,在100—500 Hz的刺激频率下,通过听性脑干反应(Auditory Evoked Potential, AEP法)测定其听力阈值。结果显示,长江鲟的最敏感频率为300 Hz,声压为(133±0.5) dB,听力曲线呈“V”型,听觉阈值随着频率的不同而发生变化。总体看,长江鲟听觉阈值较高,听力较弱,不能听到500 Hz以上的声音,其中,长江鲟的听觉阈值与湖鲟和匙吻鲟等鲟鱼类基本相似,但比长江中常见的淡水鱼类的听觉阈值高、听频范围窄。研究结果将为长江鲟的野外放归和种群重建提供重要基础资料,为评价涉渔工程建设运行对长江鱼类的影响提供基础数据支撑。

As an important “golden waterway” in China, the Yangtze River has suffered more and more destruction by human activities, such as ship transportation, channel improvement, bridge construction, hydraulic operations, dock loading and unloading, all of those caused noise pollution and influenced the fish lived in the river, even caused fish death. Acipenser dabryanus Dumeril as an important fish in the Yangtze River, its necessary to evaluate how the noise effects it. Based on this, in order to simulate the natural noise environment in the wild, the indoor noise control was used to this experiment, a stimulation frequency of 100—500 Hz was set, the Auditory Evoked Potential was used to test the threshold of juvenile Yangtze sturgeon(Acipenser dabryanus Dumeril). The results showed that the most sensitive frequency of the Acipenser dabryanus Dumeril is 300 Hz, the sound pressure is(133±0.5) dB, the hearing curve of Acipenser dabryanus Dumeril is a “V”-shaped. Different from other fishes, the Acipenser dabryanus Dumeril has a higher hearing threshold, but it cannot hear frequency above 500 Hz. Compared with the Acipenser fulvescens and Aspiolucius merzbacheri, the hearing thresholds between the three are similar. When compared with the common freshwater fish in the Yangtze River, the results showed that Acipenser dabryanus Dumeril has a higher threshold and narrower range of hearing frequency. Results of the experiment will provide important basic data for the protection and population reconstruction of the Acipenser dabryanus Dumeril, which also can provide basic data support for evaluating the impact of the fish-related projects of the fish lived in the Yangtze River.