Dataset for: Teaching fish new tricks - repeated exposure to a velocity barrier improves passage performance

Instream structures like culverts and dams can impede upstream fish migration, acting as environmental filters that only allow onward migration of individuals that can successfully pass them. Cognition and learning ability may be an important factor in determining if a fish can successfully traverse such structures. This study investigated the effect of repeated exposure on passage performance of juvenile Galaxias maculatus through an experimental raceway. Over five consecutive days, individual fish were subjected to the same high-speed (0.45-0.5 m s-1) conditions within the raceway, and performance on each day was recorded. The proportion of fish successfully passing the barrier increased significantly from 40% on Day 1 to 63% on Day 5. Time-to-event analysis further revealed that by Day 5, fish successfully passed the barrier at a significantly faster rate compared to Day 1. However, repeated exposure did not significantly improve approach or entry rates into the raceway. Fish length influenced approach rates, but not entry or passage rates. These findings suggest that cognition and spatial memory play a role in improving passage performance through velocity barriers, but other factors such as attraction flows may also play an important role in successful passage outcomes.诸如涵洞与水坝在内的河道构筑物会阻碍鱼类向上游洄游，相当于一类环境过滤筛，仅允许可成功通过该构筑物的个体继续完成洄游。认知能力与学习能力，或是决定鱼类能否成功穿越此类构筑物的关键影响因素之一。本研究以幼年期条纹南乳鱼（Galaxias maculatus）为实验对象，借助实验水槽探究了重复暴露对其过障通行表现的影响。实验连续开展五日，每条受试鱼均在水槽中处于相同的高速水流环境（0.45~0.5 m·s⁻¹），并记录其每日的通行表现。成功穿越障碍物的个体占比从第1日的40%显著提升至第5日的63%。事件发生时间分析进一步显示，相较于第1日，至第5日时鱼类成功穿越障碍物的速率显著加快。但重复暴露并未显著提升鱼类趋近水槽或进入水槽的比率。鱼体长度会对鱼类的趋近率产生影响，但对其进入水槽的比率与通行率无显著作用。本研究结果表明，认知能力与空间记忆在提升鱼类穿越流速障碍的通行表现中发挥了一定作用，但诸如诱引流在内的其他因素，或许也对鱼类成功过障的结果有着重要影响。