The ciliate–metazooplankton trophic coupling is well documented from both laboratory and field experiments. The knowledge about these relationships during winter ice-covered periods is very scarce. The abundance and composition of planktonic ciliates, rotifers and crustaceans were studied during the ice-covered and ice-free periods in the Łuczański Canal (Masurian Lakeland, Poland). We hypothesised that in winter, rotifers play a major role in the top-down control of ciliates and that ciliate–metazooplankton relationships differ not only between the ice-covered and ice-free periods, but also between ice-covered months. Our study showed that ciliates formed a significant part of zooplankton biomass during the winter ice-covered period when crustaceans occurred in very low abundances. Despite cold water temperature and the presence of ice cover, time was probably a cue that initiates zooplankton development. The ciliate, rotifer and crustacean numbers and biomass, as well as chlorophyll a concentrations, were lower in February than in ice-free periods. In the winter month with ice cover, bottom-up control by resources was more important than top-down control by zooplankton grazing in regulating ciliates. In the spring month with ice cover, crustaceans and rotifers may include ciliates as an important part of their diets. In April, the studied groups of organisms were not related to each other in contrast to the summer, when zooplankton communities were closely related to each other. In autumn, rotifers may play an important role in controlling ciliates. The abundance, composition and ciliate–metazoan relationships can vary considerably not only across seasons, but also across ice-covered months.

纤毛虫-浮游动物的营养耦合在实验室和野外实验中都有很好的记录。在冬季冰雪覆盖的时期，关于这些关系的知识非常匮乏。在Łuczański运河（波兰马苏里安湖）的冰雪覆盖和无冰时期，研究了浮游纤毛虫，轮虫和甲壳类动物的丰度和组成。我们假设，在冬季，轮虫在自上而下控制纤毛的过程中起主要作用，纤毛与浮游动物的关系不仅在冰覆盖和无冰时期之间不同，而且在冰覆盖月份之间也不同。我们的研究表明，在冬季冰雪覆盖的时期，甲壳类动物以极低的丰度发生时，纤毛虫是浮游动物生物量的重要组成部分。尽管水温低且有冰盖，时间可能是引发浮游动物发展的线索。纤毛虫，轮虫和甲壳类的数量，生物量以及叶绿素2月的浓度低于无冰期。在有冰盖的冬季，在调节纤毛虫时，资源的自下而上的控制比浮游动物放牧的自上而下的控制更为重要。在有冰雪覆盖的春季，甲壳类和轮虫可能包括纤毛虫作为其饮食的重要组成部分。在四月份，与夏季相反，与浮游动物群落彼此密切相关的夏季相比，所研究的生物群彼此之间没有相关性。在秋天，轮虫可能在控制纤毛中起重要作用。丰度，组成和纤毛虫之间的关系不仅在不同季节之间都有很大差异，而且在冰雪覆盖的月份之间也可以有很大差异。