高体鳑鲏化学预警响应与“个性”行为的关联

化学通讯是水生动物最原始、最普遍和最主要的通讯方式之一。对捕食风险源的回避可以使猎物减少被捕食风险,但如果出现的化学信息并不代表真正的威胁,那么就会导致猎物减少觅食或求偶的机会,从而降低适合度。因此基于能量代价-生态收益的权衡可能导致动物行为决策与化学通讯模式的分化。"个性"行为（Personality）已被证实与动物的行为决定有关,然而,有关鱼类化学预警通讯与"个性"行为关联的研究至今鲜见报道。推测："个性"行为是鱼类的化学通讯模式多样化的重要内因。采捕了广泛分布于我国淡水水域的野生高体鳑鲏（Rhodeus ocellatus）并于半自然状态下探究了：（1）实验鱼对不同化学信息（池水对照组、柠檬新奇信息组、高浓度和低浓度化学预警信息（Chemical alarm cues,CAC）组）的行为响应,（2）实验鱼在新异环境（被转入新栖息地）、新异刺激（新异物理刺激）、新异食物资源下的"个性"行为及其与化学预警响应的关联。结果发现：（1）不同溶液化学信息对实验鱼静止时间与爆发游泳的变化以及摄食个体的比例等参数均有显著影响（P < 0.05）。其中,柠檬组（未知"假风险"）与对照组相比无显著差异（P > 0.05）,实验鱼对不同浓度CAC（已知"真风险"）表现出不同程度的行为响应,高浓度和低浓度CAC均导致摄食个体比例下降（P < 0.05）,但只有高浓度CAC导致静止时间和爆发游泳的变化增加（P < 0.05）。可见,实验鱼对外源化学信息有准确高效的行为应答。（2）实验鱼静止时间比对不同溶液化学预警响应的变化与新异刺激下的活跃性显著负相关（P < 0.05）,但与新异环境下的活跃性无关（P > 0.05）,提示"个性"行为与化学预警响应有关但这种关联可能又有一定的环境依赖性（例如测试环境的稳定性与可预测性）。

The link between chemical alarm cue-induced behavioral responses and personality in Rhodeus ocellatus

Chemical communication is one of the most ancestral, pervasive, and dominant form of communication for aquatic animals. Sensitive avoidance of predation risk sources allows the prey to increase their probability of survival by detecting and avoiding potential predators, but is costly in terms of reduced foraging or mating opportunities if the emerging chemical cues do not represent an actual threat. Therefore, trade-offs based on energetic costs-ecological benefits may lead to differences in an animal''s behavioral decision-making and chemical communication patterns. Personality has been shown to be involved in an animal''s behavioral decisions; however, research on the link between fish personality and the chemical alarm communication has rarely been undertaken. We hypothesized that personality is an important internal cause in the diversity of fish chemical communication patterns. In the present study, wild rose bitterling, Rhodeus ocellatus, a small freshwater fish widely distributed in China and mainly inhabiting the bottom water with low transparency, slow flow, or quiescence, were used as a model and were experimentally tested under semi-natural conditions. We aimed to (1) investigate the behavioral response of experimental fish to different chemical cues, including pool water (control group), lemon odor (novel chemical cue group), and high and low concentrations of chemical alarm cues (CAC) (risky chemical cue groups), and (2) explore personality traits of the experimental fish in novel environments (being transferred to new habitats), novel stimulus (being injected with novel physical stimulus), and novel food resources (being provided with novel food resources), and their correlations with chemical alarm cue-induced behavioral responses. Our results showed that (1) the change in time spent motionless, the change in times of burst swimming, and the percentage of feeding individuals were significantly affected by different chemical cues (P < 0.05). No significant difference was found between lemon odor group (unknown "chemical cue") and the control group (P > 0.05). The experimental fish showed different degrees of behavioral responses to different concentrations of CAC (known "risk cue"). Both high and low concentrations of CAC resulted in a decrease in the proportion of feeding individuals (P < 0.05), but only high concentrations of CAC led to an increase in the time spent motionless and a change in the times of burst swimming (P < 0.05). It could be seen that the experimental fish had accurate and efficient behavioral responses to external chemical cues. Besides, our results showed that (2) the chemical alarm cue-induced behavioral responses were negatively correlated with the activity (measured as the percentage of time spent motionless) of experimental fish under novel stimulus (P < 0.05), but were not related to the activity of experimental fish under a new environment (P > 0.05). The results suggested that fish personality was related to chemical alarm communication but the association may be changed with environmental contexts (e.g. the stability and predictability of the test environment).