Abstract:
Ernst Weber stated in 1819, based on dissections, that the swimbladder in the European wels (Silurus glanis, Siluridae) and related cyprinids serves as an eardrum and that the ossicles connecting it to the inner ear function as hearing ossicles similar to mammals. In the early 20th century, K. von Frisch showed experimentally that catfishes and cyprinids (otophysines) indeed hear excellently compared to fish taxa lacking auxiliary hearing structures (ossicles, eardrums). Knowledge on hearing in catfishes progressed in particular in the 21st century. Currently, hearing abilities (audiograms) are known in 28 species out of 13 families. Recent ontogenetic and comparative studies revealed that the ability to detect sounds of low-level and high frequencies (4-6 kHz) depends on the development of Weberian ossicles. Species with a higher number of ossicles and larger bladders hear better at higher frequencies (>1 kHz). Hearing sensitivities are furthermore affected by ecological factors. Rising temperatures increase, whereas various noise regimes decrease hearing. Exposure to high-noise levels (>150 dB) for hours result in temporary thresholds shifts (TTS) and recovery of hearing after several days. Low-noise levels reduce hearing abilities due to masking without a TTS. Furthermore, auditory evoked potential (AEP) experiments reveal that the temporal patterns of fish-produced pulsed stridulation and drumming sounds are represented in their auditory pathways, indicating that catfishes are able to extract important information for acoustic communication. Further research should concentrate on inner ears to determine whether the diversity in swimbladders and ossicles is paralleled in the inner ear fine structure.
摘要:
恩斯特·韦伯在1819年说,基于解剖,欧洲游泳中的游泳者(Silurusglanis,Siluridae)和相关的cyprinids充当耳膜,将其连接到内耳的小骨充当类似于哺乳动物的听力小骨。在20世纪初,K.vonFrisch通过实验表明,与缺乏辅助听觉结构的鱼类类群相比,cat鱼和cyprinids(耳光)确实听得很好(小骨,耳膜)。特别是在21世纪,关于鲶鱼听力的知识取得了进展。目前,听力能力(听力图)在13个科的28个物种中已知。最近的本体遗传学和比较研究表明,检测低频和高频(4-6kHz)声音的能力取决于韦伯小骨的发展。小骨数量较多,膀胱较大的物种在较高的频率(>1kHz)下听起来更好。听力敏感性还受到生态因素的影响。气温上升,而各种噪音制度会降低听力。暴露于高噪声水平(>150dB)数小时会导致暂时的阈值偏移(TTS)并在几天后恢复听力。低噪声水平由于没有TTS的掩蔽而降低听力能力。此外,听觉诱发电位(AEP)实验表明,鱼产生的脉冲声和鼓声的时间模式在其听觉通路中表示,这表明鲶鱼能够为声学通信提取重要信息。进一步的研究应集中于内耳,以确定游泳膀胱和小骨的多样性是否在内耳精细结构中平行。