Popper A N
Department of Biology, Univesity of Maryland, College Park, MD 20742, USA.
Philos Trans R Soc Lond B Biol Sci. 2000 Sep 29;355(1401):1277-80. doi: 10.1098/rstb.2000.0683.
The past decade has seen a wealth of new data on the auditory capabilities and mechanisms of fishes. We now have a significantly better appreciation of the structure and function of the auditory system in fishes with regard to their peripheral and central anatomy, physiology, behaviour, sound source localization and hearing capabilities. This paper deals with two of the newest of these findings, hair cell heterogeneity and the detection of ultrasound. As a result of this recent work, we now know that fishes have several different types of sensory hair cells in both the ear and lateral line and there is a growing body of evidence to suggest that these hair cell types arose very early in the evolution of the octavolateralis system. There is also some evidence to suggest that the differences in the hair cell types have functional implications for the way the ear and lateral line of fishes detect and process stimuli. Behavioural studies have shown that, whereas most fishes can only detect sound to 1-3 kHz, several species of the genus Alosa (Clupeiformes, i.e. herrings and their relatives) can detect sounds up to 180 kHz (or even higher). It is suggested that this capability evolved so that these fishes can detect one of their major predators, echolocating dolphins. The mechanism for ultrasound detection remains obscure, though it is hypothesized that the highly derived utricle of the inner ear in these species is involved.
在过去十年里，我们获得了大量关于鱼类听觉能力和机制的新数据。现在，我们对鱼类听觉系统的结构和功能有了显著更深入的认识，涉及它们的外周和中枢解剖学、生理学、行为、声源定位及听力能力。本文探讨其中两个最新发现，即毛细胞异质性和超声波检测。基于近期的这项研究工作，我们现在知道鱼类的耳朵和侧线中存在几种不同类型的感觉毛细胞，并且越来越多的证据表明这些毛细胞类型在八侧线系统的进化过程中很早就出现了。也有一些证据表明，毛细胞类型的差异对鱼类耳朵和侧线检测及处理刺激的方式具有功能意义。行为学研究表明，虽然大多数鱼类只能检测到1至3千赫兹的声音，但西鲱属（鲱形目，即鲱鱼及其近亲）的几个物种能够检测到高达180千赫兹（甚至更高）的声音。有人认为这种能力的进化是为了使这些鱼类能够检测到它们的主要捕食者之一——使用回声定位的海豚。尽管据推测这些物种内耳高度特化的椭圆囊与此有关，但超声波检测的机制仍然不明。
