Tintinnids (Ciliophora) are important microzooplankton grazers. In the Southern Ocean, they are found in the Antarctic Zone, Polar Front and Subantarctic Zone. The Antarctic Zone encompasses large gyres (Weddell Gyre and Ross Gyre) and the Antarctic Slope Current around the continent. The influence of these water masses on tintinnid communities has not been studied. This study investigated the tintinnid community structure in the Weddell and Cosmonaut seas in the summer of 2022. In the Weddell Gyre, tintinnid abundance was significantly lower in the interior than at the fronts. The dominant species differed between the east and west fronts: the proportion of Codonellopsis gaussi was high at the west front, whilst Laackmanniella naviculaefera, Salpingella sp. and Salpingella faurei showed high abundances at the east front. Tintinnid communities varied from inshore to offshore of the Cosmonaut Sea, possibly because of the influence from the Antarctic Slope Current and Antarctic Circumpolar Current. The Antarctic Slope Current was characterized by the occurrence of Cymatocylis drygalskii, whilst the Antarctic Circumpolar Current was characterized by Codonellopsis glacialis, Cymatocylis convallaria and Cy. calyciformis. We proposed that Cy. drygalskii can be used as an indicator of the Antarctic Slope Current. Moreover, we classify polymorphic C. gaussi into three types, in accordance with their loricae, and report their distribution characteristics in water masses. Our results contribute to a better understanding of tintinnid horizontal distribution in different parts of the Weddell Gyre and water masses and serve as a baseline for future studies of pelagic community responses to climate change in the Southern Ocean.

Tintinnids (Ciliophora) 是重要的微型浮游动物食草动物。在南大洋，它们被发现于南极区、极锋和亚南极区。南极区包括大型环流（威德尔环流和罗斯环流）和围绕大陆的南极坡流。这些水团对丁丁尼科动物群落的影响尚未被研究。这项研究调查了 2022 年夏季威德尔海和宇航员海的丁丁鱼群落结构。在威德尔环流中，内陆丁丁鱼丰度明显低于前沿。东西锋区优势种存在差异： 西锋党魁所占比重 较高，而 Laackmanniella naviculaefera、  Salpingella  sp．Salpingella  faurei 在东线表现出高丰度。宇航员海的近海和近海丁丁尼鱼群落各不相同，这可能是由于南极坡流和南极绕极流的影响。南极坡流的特征是 Cymatocylis drygalskii的出现，而南极绕极流的特征是 Codonellopsis glacialis、  Cymatocylis convalria 和 Cy。萼状。我们建议 Cy. drygalskii 可用作南极坡流的指标。此外，我们  根据其位置将多态性C. gaussi分为三种类型，并报告了它们在水团中的分布特征。我们的研究结果有助于更好地了解威德尔环流和水团不同部分的丁丁鱼水平分布，并为未来研究南大洋中上层群落对气候变化的反应提供基线。