In recreational fisheries, fish often undergo catch-and-release angling, which can lead to an indirect selection response of the behavioral traits of the fish. As individuals experience high-intensity angling activities, individuals learn to avoid being selected for artificial bait again, resulting in a change in the vulnerability to angling of fish, which is partly dependent on the cognitive learning ability of the fish. Here, we examined the relationship between vulnerability to angling and learning in juvenile crucian carp (Carassius auratus) under laboratory conditions. Our study had six angling treatments with each containing different group mates (i.e., the angling stress group, all fish that only experienced repeated angling stress practice for a period of three days; the learning group, all fish that only observed individual in the angling stress group to be angled; the control group, all fish that did not undergo any angling or learning; the mixed Group 1, fish are from the control and learning groups; the mixed Group 2, fish are from the control and angling stress groups; the mixed Group 3, fish are from the learning and angling stress groups), each of which consisted of five replicates). All fish were tested for boldness before and after the previous experiences (i.e., angling stress or learning) test. Our results showed that for the stress group, the total angling time, mean individual angling time and total number of bait touches all increased from Day 1 to Day 3, and the total angling rate decreased during the three days of the angling stress practice. After encountering the previous experiences, fish in the control, stress and learning groups all had increased boldness, as assessed by a shortened percent latency to emerge from the refuge. The change in the percent latency of boldness was higher in the stress group than in the learning group, with the control group being intermediate. Furthermore, no differences in the total angling time and total number of bait touches were detected among the six angling treatments, but the stress group exhibited the longest mean individual angling time and lowest angling rate compared with the other five angling treatments, indicating that angling-stressed individuals greatly decreased their vulnerability to angling after the previous angling stress. Our results show that changes in the vulnerability of crucian carp to angling were related to previous individual angling experience but not to visual social learning.

在休闲渔业中，鱼类经常进行捕捞和放生钓鱼，这可能导致鱼类行为特征的间接选择反应。随着个体经历高强度的垂钓活动，个体学会避免再次被选作人工诱饵，导致鱼垂钓的脆弱性发生变化，这部分取决于鱼的认知学习能力。在这里，我们研究了幼鱼 ( Carassius auratus ) 垂钓脆弱性与学习之间的关系) 在实验室条件下。我们的研究有六种钓鱼治疗，每一种都包含不同的同伴（即钓鱼压力组，所有鱼只经历了三天的反复钓鱼压力练习；学习组，所有鱼只观察个体在钓鱼压力下钓鱼组；对照组，所有未进行任何钓鱼或学习的鱼；混合组 1，鱼来自控制组和学习组；混合组 2，鱼来自控制组和钓鱼压力组；混合组 3，鱼来自学习和钓鱼压力组），每个组由 5 个重复组成）。在之前的经验（即钓鱼压力或学习）测试之前和之后测试所有鱼的胆量。我们的结果表明，对于压力组，总钓鱼时间，从第1天到第3天，平均个体垂钓时间和总触饵次数均增加，垂钓应力练习三天总垂钓率下降。在经历了之前的经历之后，控制组、压力组和学习组中的鱼的胆量都增加了，这是通过缩短从避难所出现的延迟百分比来评估的。压力组的大胆潜伏期百分比的变化高于学习组，而对照组处于中等水平。此外，六种钓鱼处理的总钓鱼时间和诱饵接触总数没有差异，但与其他五种钓鱼处理相比，应激组表现出最长的平均个体钓鱼时间和最低的钓鱼率，表明钓鱼压力大的个体在之前的钓鱼压力之后大大降低了他们对钓鱼的脆弱性。我们的研究结果表明，鲫鱼对钓鱼的脆弱性的变化与以前的个人钓鱼经验有关，但与视觉社会学习无关。