Abstract：
Zoothamnium intermedium is an obligate epibiont ciliate and has been found in a diverse array of hosts and environments. Different studies have reported conflicting distribution patterns and host preferences, even though studies in Chesapeake Bay have suggested that the ciliate has a strong host specificity for two calanoid copepod species. We examined the life cycle, host preferences, and ecological conditions conducive to Z. intermedium presence on copepods in Chesapeake Bay, the largest estuary in North America. The York River tributary was sampled biweekly from fall 2014 through summer 2015 for plankton, peritrichs and bacteria in the water column. Bacterial abundance in the water column peaked in fall and late spring, coinciding with increased abundance and species richness of non-epibiont peritrichs. Among the plankton, only the calanoid copepods Acartia tonsa and Centropages hamatus were colonized by Z. intermedium. The peritrich epibiont displayed higher colonization rates on C. hamatus even when A. tonsa was far more abundant. Multivariate correlation analysis of infestation prevalence on A. tonsa showed a strong correlation with dissolved oxygen, salinity and water temperature. Such correlations, along with differences in host species biology, might be driving the seasonality of this epibiotic relationship.
摘要：
中间Zoothamnium是一种专性的外生纤毛虫，已在多种宿主和环境中发现。不同的研究报告了相互矛盾的分布模式和宿主偏好，尽管在切萨皮克湾进行的研究表明，纤毛虫对两种类of足类具有很强的宿主特异性。我们检查了生命周期，主机首选项,以及有利于Z.ChesapeakeBay足类中间存在的生态条件，北美最大的河口。从2014年秋季到2015年夏季，每两周对约克河支流进行一次浮游生物采样，水柱中的细菌和细菌。水柱中的细菌丰度在秋天和春末达到顶峰，与非附生附生的丰度和物种丰富度增加相吻合。在浮游生物中,Z.中只定殖了类co足类Acartiatonsa和Centropageshamatus。即使在A.tonsa丰富得多的情况下，富含环境的外生体在C.hamatus上也显示出更高的定殖率。多因子相关分析显示，与溶氧有很强的相关性，盐度和水温。这种相关性，随着宿主物种生物学的差异，可能会推动这种表观生物关系的季节性。
