Our results are the first insight into groundwater copepods of the Polish Lowland. The sampling was conducted in 28 wells in north-eastern Poland, and Copepoda were present in 16 wells. We have identified six Copepoda species and one Cladocera. We have classified four species as stygophiles—Eucyclops serrulatus, Diacyclops bisetosus, Diacyclops crassicaudis, and Cyclops furcifer. These species were frequently found in studied wells of different regions of north-eastern Poland, often in high numbers, and females with egg sacs were observed. We present a detailed morphological description of these species, together with molecular characteristics based on mitochondrial DNA markers (COI gene) for E. serrulatus, D. bisetosus, and D. crassicaudis, and 12S ribosomal RNA for C. furcifer. We also present the development of abnormal structures in one specimen of D. crassicaudis, where the upper part of furcal rami was fused to form a single plate.

中文翻译：

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首次深入了解波兰低地的地下水桡足类

我们的结果是对波兰低地地下水桡足类动物的首次了解。在波兰东北部的 28 口井中进行了采样，在 16 口井中存在 Copepoda。我们已经确定了六种桡足类和一种枝角类。我们已将四种物种归类为 stygophiles - Eucyclops serrulatus、Diacyclops bisetosus、Diacyclops crassicaudis和Cyclops furcifer . 这些物种经常在波兰东北部不同地区的研究井中发现，数量通常很高，并且观察到带有卵囊的雌性。我们提出这些物质的详细形态描述，其中基于线粒体DNA标记（COI基因），用于分子特征一起ë。锯齿草，D。biseto是我们,和D . crassicaud我š ，和12S核糖体RNA Ç。弗西弗。我们还介绍了D. crassicaudis 的一个标本中异常结构的发展，其中分枝的上部融合形成单个板。