Effects of temperature, season and locality on wasting disease in the keystone predatory sea star Pisaster ochraceus
Effects of temperature, season and locality on wasting disease in the keystone predatory sea star Pisaster ochraceus
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DOI：
10.3354/dao02125
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发表时间：
2009-11-09
影响因子：
1.4
通讯作者：
Harley, Christopher D. G.
中科院分区：
文献类型：
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作者：
Bates, Amanda E.;Hilton, Brett J.;Harley, Christopher D. G.
这项研究调查了温哥华岛(加拿大不列颠哥伦比亚省)外西海岸东北部太平洋拱心石捕食性海星翡翠鱼的消瘦疾病。为了量化温度、季节和地理位置对稻瘟病菌易损性的影响，我们在夏初和夏末进行了调查和试验。为了验证温度的小幅升高会导致感染强度增加的预测，我们在实验室里放置了不同温度的海星，并将海星关在2个深度的笼子里。温热处理的患病率和感染强度始终较高，性别间和体型越大，感染率和感染强度均无差异。疾病的影响也因季节和地区而异。水族箱中保存的标本在6月份的发病率和感染强度明显高于8月份。此外，来自避风港的海星在夏末表现出明显较高的疾病患病率，而暴露在海浪中的地点的疾病患病率一直较低。繁殖潜力、寄主条件和/或生理适应的季节性变化，以及不同地区之间的环境状况差异，可能会影响衰减性疾病的动态。这些结果表明，气温的小幅上升可能会导致Pisaster因消耗性疾病而大量死亡，脆弱性可能在春季和避难地的种群中达到高峰。这是北美西海岸发现的最北端的星形总科昆虫。
This study investigates wasting disease in the northeast Pacific keystone predatory sea star Pisaster ochraceus on the outer west coast of Vancouver Island (British Columbia, Canada). To quantify the effects of temperature, season and locality on the vulnerability of P. ochraceus to wasting disease, we conducted surveys and experiments in early and late summer. To test the prediction that a small increase in temperature would result in heightened infection intensities, we housed sea stars at different temperatures in the laboratory and caged sea stars subtidally at 2 depths. Prevalence and infection intensity were always higher in warm temperature treatments and did not differ between the sexes or with increasing size. Disease effects also varied with season and locality. Specimens held in aquaria displayed significantly higher disease prevalence and infection intensity in June versus August. Furthermore, sea stars from a sheltered inlet showed markedly higher prevalence of the disease in late summer, while wave-exposed sites had consistently low disease prevalence. Seasonal changes in reproductive potential, host condition and/or physiological acclimation, as well as differences in environmental regime among localities, may impact the dynamics of wasting disease. These results demonstrate that small increases in temperature could drive mass mortalities of Pisaster due to wasting disease, with vulnerability possibly reaching a peak in spring and in populations from sheltered localities. This is the most northern report of wasting disease in the class Asteroidea on the west coast of North America.