Ciliate−copepod epibiosis is a common but poorly understood phenomenon in the aquatic environment. This study investigated the prevalence of ciliate infestation on copepods in the Klang Strait, Straits of Malacca. We hypothesized that anthropogenic impacts in the strait have increased ciliate epibiont infestation. Zooplankton samples were collected in 2013−2014 and compared to samples collected from the same 5 stations in 1985−1986, prior to the establishment of the Kapar Power Station (KPS). The 5 sampling sites, including 1 impact (I) and 4 control (C1−C4) stations, were located along an 18 km transect ranging from near the KPS (I) to progressively further offshore (C4). Ciliate epibionts on the copepods belonged to an unidentified Zoothamnium species; 14 copepod species were infested by this ciliate. The highest infestation prevalence occurred in 5 key calanoid species: Paracalanus aculeatus, Acrocalanus gibber, Labidocera euchaeta, Parvocalanus crassirostris and Subeucalanus subcrassus. Before-after-control-impact-pairs (BACI) analysis showed that infestations were more prevalent at all stations in 2013−2014 compared to 1985−1986 and were lowest at or nearest the impact site. The prosome of the copepod was the body part most susceptible to attachment by the ciliate. Generally, the density of infested copepods and their epibiont loads were positively correlated with copepod abundance. Only the density of infested A. gibber showed a significant positive relationship with water temperature, while in P. aculeatus the infested copepod density was significantly correlated with phytoplankton abundance after a lag of 2 mo. We suggest that sea warming and eutrophication in recent years have increased ciliate−copepod epibiosis in the Klang Strait.

中文翻译：

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有柄纤毛虫 Zoothamnium sp. 的过去和现在侵染。巴生海峡的桡足类动物

纤毛虫-桡足类外生是水生环境中一种常见但知之甚少的现象。本研究调查了马六甲海峡巴生海峡桡足类纤毛虫感染的流行情况。我们假设海峡中的人为影响增加了纤毛虫外生体的侵染。浮游动物样本于 2013-2014 年收集，并与 Kapar 发电站 (KPS) 建立之前的 1985-1986 年从相同 5 个站收集的样本进行比较。5 个采样点，包括 1 个影响 (I) 和 4 个控制 (C1-C4) 站，位于从 KPS (I) 附近到离岸 (C4) 附近的 18 公里断面。桡足类上的纤毛虫外生体属于一种身份不明的 Zoothamnium 物种；这种纤毛虫侵染了 14 种桡足类动物。最高的侵染发生率发生在 5 种主要的海藻中：尖刺拟螯虾、长尾刺海葵、紫花唇角海棠、细小海葵和亚拟南缘海螯虾（Parvocalanus crassirostris）。前后对照影响对 (BACI) 分析表明，与 1985-1986 年相比，2013-2014 年所有站点的侵染更为普遍，并且在影响地点或最近的影响地点最低。桡足类的前体是最容易被纤毛虫附着的身体部位。一般来说，受感染桡足类的密度及其表皮负载量与桡足类丰度呈正相关。只有受侵染的 A.gibber 的密度与水温呈显着正相关，而在 P. aculeatus 中，受侵染的桡足类密度在滞后 2 个月后与浮游植物丰度显着相关。