Habitat selection by aquatic organisms is dependent on the availability of adequate conditions to support life and the benefits that the habitat provides. Contaminated environments tend to be less attractive to organisms because reduced habitat quality leads to increased maintenance costs. Consequently, reduced colonization of such disturbed habitats is an expected response. However, colonization has been understudied as an ecotoxicological test endpoint, despite its proven ability to assess habitat selection by populations across various taxa. The aim of the present study was to investigate whether previous exposure to copper could alter the colonization behavior of the freshwater prawn along a non-forced exposure gradient of interconnected copper-contaminated habitats (0 to 500 µg/L) due to physiological and behavioral impairments. To assess this, post-larvae of were pre-exposed to 0, 50, 250 and 500 µg/L copper for a maximum period of 48 h. The physiological status and motility of the organisms after pre-exposure to copper were evaluated using behavioral endpoints (swimming activity by video tracking) and biochemical biomarkers (biotransformation, oxidative stress and neurotoxicity). The results indicated that pre-exposure to copper (at concentrations of 0, 50 and 500 µg/L) significantly influenced the median colonization concentration (CC50), which decreased from 270 µg/L to 109 µg/L. None of the assessed swimming parameters (speed, motility rate, exploration rate, and total distance) were affected by the pre-exposure to copper (0, 50 and 250 µg/L). Biochemically, cholinesterase levels were only affected in the prawn population exposed to 250 µg/L of copper. The present study provides a better understanding of the relevance of colonization as an ecotoxicological endpoint for assessing the spatial distribution of populations, including both new inhabitants and previously exposed organisms, in recovering habitats.

中文翻译：

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使用模型毒物铜和定植作为测试终点来评估罗氏沼虾的栖息地选择：之前的暴露是否决定了生化和行为反应？


水生生物对栖息地的选择取决于是否有足够的条件来支持生命以及栖息地提供的好处。受污染的环境往往对生物体吸引力较小，因为栖息地质量下降会导致维护成本增加。因此，减少此类受干扰栖息地的殖民化是预期的反应。然而，尽管殖民化已被证明能够评估不同类群种群的栖息地选择，但它仍被作为一种生态毒理学测试终点进行了充分研究。本研究的目的是调查先前接触铜是否会由于生理和行为障碍而改变淡水虾沿着相互连接的铜污染栖息地的非强迫暴露梯度（0至500微克/升）的定殖行为。为了评估这一点，将后期幼虫预先暴露于 0、50、250 和 500 µg/L 的铜，最长持续时间为 48 小时。使用行为终点（通过视频跟踪进行游泳活动）和生化生物标志物（生物转化、氧化应激和神经毒性）评估预接触铜后生物体的生理状态和运动性。结果表明，预接触铜（浓度为 0、50 和 500 µg/L）显着影响中位定植浓度 (CC50)，从 270 µg/L 降至 109 µg/L。所评估的游泳参数（速度、运动率、探索率和总距离）均不受预先暴露于铜（0、50 和 250 µg/L）的影响。从生化角度来看，胆碱酯酶水平仅在暴露于 250 µg/L 铜的虾群中受到影响。 本研究更好地理解了定植作为生态毒理学终点的相关性，用于评估种群空间分布，包括新居民和先前暴露的生物体在恢复栖息地时的空间分布。