Ladich F
Institute of Zoology, University of Vienna, Austria.
Philos Trans R Soc Lond B Biol Sci. 2000 Sep 29;355(1401):1285-8. doi: 10.1098/rstb.2000.0685.
Fishes have evolved a diversity of sound-generating organs and acoustic signals of various temporal and spectral content. Additionally, representatives of many teleost families such as otophysines, anabantoids, mormyrids and holocentrids possess accessory structures that enhance hearing abilities by acoustically coupling air-filled cavities to the inner ear. Contrary to the accessory hearing structures such as Weberian ossicles in otophysines and suprabranchial chambers in anabantoids, sonic organs do not occur in all members of these taxa. Comparison of audiograms among nine representatives of seven otophysan families from four orders revealed major differences in auditory sensitivity, especially at higher frequencies (> 1 kHz) where thresholds differed by up to 50 dB. These differences showed no apparent correspondence to the ability to produce sounds (vocal versus non-vocal species) or to the spectral content of species-specific sounds. In anabantoids, the lowest auditory thresholds were found in the blue gourami Trichogaster trichopterus, a species not thought to be vocal. Dominant frequencies of sounds corresponded with optimal hearing bandwidth in two out of three vocalizing species. Based on these results, it is concluded that the selective pressures involved in the evolution of accessory hearing structures and in the design of vocal signals were other than those serving to optimize acoustic communication.
鱼类进化出了多种多样的发声器官以及具有各种时间和频谱内容的声学信号。此外，许多硬骨鱼科的代表，如鲤形目鱼类、攀鲈科鱼类、裸背电鳗科鱼类和金鳞鱼科鱼类，拥有辅助结构，通过将充满空气的腔室与内耳进行声学耦合来增强听力。与鲤形目鱼类的韦氏小骨和攀鲈科鱼类的鳃上腔等辅助听觉结构不同，发声器官并非在这些分类群的所有成员中都存在。对来自四个目七个鲤形目鱼类家族的九个代表的听力图进行比较发现，听觉敏感性存在重大差异，尤其是在较高频率（>1kHz）时，阈值差异高达50dB。这些差异与发声能力（发声物种与不发声物种）或物种特异性声音的频谱内容没有明显对应关系。在攀鲈科鱼类中，最低听觉阈值出现在蓝曼龙（Trichogaster trichopterus）中，这是一种被认为不发声的物种。在三个发声物种中的两个物种中，声音的主导频率与最佳听力带宽相对应。基于这些结果，可以得出结论，辅助听觉结构进化和发声信号设计中涉及的选择压力并非用于优化声学通讯的那些压力。
