运动是几乎所有动物行为的基础。进化导致了无脊椎动物中推进机制的一些非凡专业化,包括德古拉蚂蚁的下颌骨和手枪虾的爪。相比之下,脊椎动物的骨骼运动被认为受到肌肉速度的限制,饱和约250赫兹。这里,我们描述了Danionella大脑的独特推进机制,一条只有12毫米长的微型鲤鱼,产生超过140dB的高振幅声音(re.1µPa,在一个身体长度的距离处)。使用高速视频的组合,微型计算机断层扫描(micro-CT),RNA分析,和有限差分模拟,我们发现大脑D.cerebrum采用了一种独特的声音产生机制,涉及到鼓起的软骨,一根专门的肋骨,和适应低疲劳的专用肌肉。这个装置加速击鼓软骨超过2000克,向游泳膀胱射击以产生快速的,响亮的脉搏。这些脉冲被链接在一起,以进行双侧交替或单侧肌肉收缩的调用。D.大脑使用这种显着的机制与特定的声音交流。
Motion is the basis of nearly all animal behavior. Evolution has led to some extraordinary specializations of propulsion mechanisms among invertebrates, including the mandibles of the dracula ant and the claw of the pistol shrimp. In contrast, vertebrate skeletal movement is considered to be limited by the speed of muscle, saturating around 250 Hz. Here, we describe the unique propulsion mechanism by which Danionella cerebrum, a miniature cyprinid fish of only 12 mm length, produces high amplitude sounds exceeding 140 dB (re. 1 µPa, at a distance of one body length). Using a combination of high-speed video, micro-computed tomography (micro-CT), RNA profiling, and finite difference simulations, we found that D. cerebrum employ a unique sound production mechanism that involves a drumming cartilage, a specialized rib, and a dedicated muscle adapted for low fatigue. This apparatus accelerates the drumming cartilage at over 2,000 g, shooting it at the swim bladder to generate a rapid, loud pulse. These pulses are chained together to make calls with either bilaterally alternating or unilateral muscle contractions. D. cerebrum use this remarkable mechanism for acoustic communication with conspecifics.