Data from: Acquired versus innate prey capturing skills in super-precocial live-bearing fish

Live-bearing fish start hunting for mobile prey within hours after birth, an example of extreme precociality. Because prenatal, in utero, development of this behaviour is constrained by the lack of free-swimming sensory-motor interactions, immediate success after birth depends on innate, evolutionarily acquired patterns. Optimal performance however requires flexible adjustment to an unpredictable environment. To distinguish innate from postnatally developing patterns we analysed over 2000 prey capture events for 28 metallic livebearers (Girardinus metallicus; Poeciliidae), during their first 3 days after birth. We show that the use of synchronous pectoral fin beats for final acceleration and ingestion is fixed and presumably innate. It allows for direct, symmetrical control of swimming speed and direction, while avoiding head yaw. Eye movements and body curvatures, however, change considerably in the first few days, showing that eye-tail coordination requires postnatal development. The results show how successful prey captures for newborn, live-bearing fish are based on a combination of fixed motor programmes and rapid, postnatal development.

胎生鱼类（Live-bearing fish）会在出生后数小时内便开始捕猎移动猎物，这是极端早熟性（precociality）的典型范例。由于该行为在产前子宫内的发育会因缺乏自由游动的感觉运动交互而受到限制，幼体出生后的即时捕猎成功率便依赖于先天的、经进化获得的行为模式。然而，要达成最优捕猎表现，则需要对不可预测的环境进行灵活调整。为区分先天行为模式与产后发育的行为模式，我们对28尾金属花鳉（Girardinus metallicus；花鳉科Poeciliidae）在出生后前3天内的2000余次捕猎事件进行了分析。我们发现，用于最终加速与摄食的同步胸鳍摆动模式是固定不变的，且大概率为先天固有。该模式可实现对游泳速度与方向的直接、对称控制，同时避免头部偏航。然而，幼体的眼部运动与躯体弯曲在最初数天内会发生显著变化，这表明眼尾协调能力需要通过产后发育才能完善。本研究结果表明，新生胎生鱼类的成功捕猎行为，是固定运动程序与快速产后发育二者共同作用的结果。