Fine M L, Malloy K L, King C B, Mitchell S L, Cameron T M
Department of Biology, Virginia Commonwealth University, Richmond 23284-2012, USA.
J Comp Physiol A. 2001 Jun;187(5):371-9. doi: 10.1007/s003590100209.
Although sound-producing (sonic) muscles attached to fish swimbladders are the fastest known vertebrate muscles, the functional requirement for such extreme speed has never been addressed. We measured movement of the swimbladder caused by sonic muscle stimulation in the oyster toadfish Opsanus tau and related it to major features of the sound waveform. The movement pattern is complex and produces sound inefficiently because the sides and bottom of the bladder move in opposite in and out directions, and both movement and sound decay rapidly. Sound amplitude is related to speed of swimbladder movement, and slow movements do not produce perceptible sound. Peak sound amplitude overlaps fundamental frequencies of the male's mating call because of muscle mechanics and not the natural frequency of the bladder. These findings suggest that rapid muscle speed evolved to generate sound from an inefficient highly damped system.
尽管附着在鱼类鱼鳔上的发声（声波）肌肉是已知速度最快的脊椎动物肌肉，但这种极端速度的功能需求从未得到探讨。我们测量了在牡蛎蟾鱼（Opsanus tau）中由声波肌肉刺激引起的鱼鳔运动，并将其与声音波形的主要特征联系起来。运动模式很复杂，并且产生声音的效率很低，因为鱼鳔的侧面和底部以相反的方向向内和向外移动，而且运动和声音都迅速衰减。声音振幅与鱼鳔运动速度有关，缓慢的运动不会产生可察觉的声音。由于肌肉力学而非鱼鳔的固有频率，声音振幅峰值与雄性求偶叫声的基频重叠。这些发现表明，快速的肌肉速度是为了从不高效的高阻尼系统中产生声音而进化出来的。
