Population outbreaks of the corallivorous crown-of-thorns seastar (CoTS; Acanthaster spp.) are significant threats to the Indo-Pacific reefs. Although recent research demonstrated that environmental DNA (eDNA) techniques could improve CoTS monitoring, the interpretation of surveillance results has been limited by uncertainties about eDNA dynamics. Here, we conducted aquarium experiments to identify biotic and abiotic factors affecting the shedding and degradation rates of CoTS eDNA. In the first experiment, we investigated the effect of two temperatures (24 and 28 °C) and three feeding treatments (no coral, coral accessible and coral inaccessible) on eDNA shedding rate of laboratory-raised 8-month-old juvenile CoTS. In the second experiment, we quantified CoTS eDNA degradation rate under three temperatures (24, 26 and 28 °C). We found that eDNA shedding rate was affected by feeding treatment (p < 0.0001) but not temperature. Specifically, the shedding rate under coral accessible treatment was about seven times higher than that of coral inaccessible treatment (p < 0.0001), whereas the presence of coral reduced the shedding rate by half (coral inaccessible vs no coral, p = 0.0249). Degradation of CoTS eDNA was rapid (half-life = 14 h) and not affected by temperature. Our results demonstrated that feeding activity increased eDNA release, but some of the released DNA was lost, potentially due to binding to coral surface mucus layer or skeleton. The rapid degradation rate indicated that results of eDNA surveillance likely reflects recent and local occurrence of CoTS. Although further testing is needed, this study provided support for using eDNA as a novel detection tool for early life stages of CoTS on coral reefs.

珊瑚状荆棘王冠海星的种群暴发（CoTS; Acanthasterspp。）是对印度太平洋礁石的重大威胁。尽管最近的研究表明环境DNA（eDNA）技术可以改善CoTS监测，但是对监测结果的解释受到eDNA动态不确定性的限制。在这里，我们进行了水族馆实验，以确定影响CoTS eDNA脱落和降解速率的生物和非生物因素。在第一个实验中，我们研究了两种温度（24和28°C）和三种喂养方法（无珊瑚，无珊瑚和无珊瑚）对实验室饲养的8个月大幼体CoTS的eDNA脱落速率的影响。在第二个实验中，我们量化了在三种温度（24、26和28°C）下CoTS eDNA的降解速率。我们发现eDNA脱落率受饲喂处理的影响（p <0.0001），而不是温度。具体而言，采用珊瑚无障碍治疗方法的脱落率大约是无法利用珊瑚的治疗方法的脱落率的七倍（p  <0.0001），而存在珊瑚会使珊瑚的脱落率降低了一半（珊瑚难以接近与无珊瑚，p = 0.0249）。CoTS eDNA降解迅速（半衰期= 14 h），不受温度影响。我们的结果表明，摄食活性增加了eDNA的释放，但某些释放的DNA丢失了，可能是由于与珊瑚表面粘液层或骨骼的结合所致。快速降解率表明eDNA监测的结果可能反映了CoTS的近期和局部发生。尽管需要进一步测试，但这项研究为将eDNA用作CoTS在珊瑚礁生命早期阶段的新型检测工具提供了支持。