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    食物资源可预测性和捕食胁迫对中华倒刺鲃幼鱼生长和生存能力的影响

    FOOD RESOURCE PREDICTABILITY AND PREDATION STRESS ON GROWTH AND SURVIVAL OF JUVENILE SPINIBARBUS SINENSIS

    • 摘要: 为探究食物资源在获取时间上的可预测性与捕食胁迫对鱼类生长和生存的影响及其生理与行为机制, 本研究以中华倒刺鲃(Spinibarbus sinensis)幼鱼为研究对象, 采用食物资源可预测性(固定/随机时间投喂)和捕食胁迫(有/无捕食者视觉刺激)两因素设计, 共设置4个处理组, 开展为期60d的生长实验; 结束后分别进行了标准代谢率(SMR)、行为特征、生化指标及反捕食生存能力的测定。结果显示: 与食物资源可预测组相比, 不可预测组中华倒刺鲃的特定生长率、增重率和摄食效率均显著提高, 而摄食率和超氧化物歧化酶活性显著降低, 血浆皮质醇水平显著升高。捕食胁迫显著抑制了中华倒刺鲃的生长和冒险行为, 且降低了其反捕食生存能力; 此外, 捕食胁迫仅显著提高了食物不可预测组的SMR。结果表明, 尽管食物资源在时间上的不可预测被中华倒刺鲃感知为一种环境压力, 但其仍能够通过调整能量利用策略来促进生长; 相比之下, 捕食胁迫可能迫使能量更多地分配于警觉性的维持和应激响应, 最终抑制了生长并降低了后续的生存能力。研究结果提示, 食物资源获取时间的不确定性可能加剧捕食胁迫对鱼类个体的影响。

       

      Abstract: To investigate the effects of food resource predictability and predation stress on fish growth and survival, as well as the underlying physiological and behavioral mechanisms, juvenile qingbo (Spinibarbus sinensis) were subjected to a two-factor experimental design involving food resource predictability (fixed vs. random feeding schedules) and predation stress (with or without visual predator cues). Four treatment groups were established and reared for 60 days. At the end of the growth experiment, standard metabolic rate (SMR), behavioral traits, biochemical parameters, and antipredator survival were assessed. Compared with the predictable food group, fish in the unpredictable food group exhibited significantly higher specific growth rate, weight gain rate, and feed efficiency, but significantly lower feeding rate and superoxide dismutase (SOD) activity, accompanied by significantly elevated plasma cortisol levels. Predation stress significantly inhibited growth and risk-taking behavior and reduced antipredator survival. In addition, predation stress significantly increased SMR only in fish exposed to unpredictable food resources. These findings suggest that although unpredictable food resources were perceived as an environmental stressor by qingbo, the fish were still able to promote growth by adjusting their energy allocation strategy. In contrast, predation stress likely diverted more energy toward maintaining vigilance and stress responses, ultimately suppressing growth and reducing subsequent survival. Furthermore, the uncertainty in food availability may exacerbate the negative effects of predation stress on individual fish.

       

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