In material collected in the Losambila river, a small tributary of the Congo River at Yangambi (Tshopo Province, Democratic Republic of the Congo), an unusual Eunotia species was observed. The same taxon was also detected in material taken at the beginning of 2018 in a small tributary of the Luapula river in the Haut-Katanga Province in the South of DR Congo. We could identify it as Eunotia enigmatica, recently described from reservoirs in south-eastern Brazil. The valve morphology of the Congolese material is compared with the Brazilian. E. enigmatica was not observed frequently but was not rare either. In two samples of the Losambila river this taxon reached up to 5.6 and 5.4 % of the total diatom assemblage. It is not the only species with a distribution known from Africa and South-America observed in the Losambila River. Encyonopsis frequentis, also described from South America, was more common than E. enigmatica in samples collected in the Tshopo Province, and reached up to 16.8% of the total diatom composition in the Losambila river. However, Encyonopsis frequentis was not observed in the samples where E. enigmatica was present. The same applies to the material from the tributary of the Luapula river where Encyonopsis frequentis was not found in the sample where E. enigmatica was present.

在扬比亚的刚果河的一个小支流洛桑比拉河（刚果民主共和国，Tshopo省）收集的材料中，观察到一种不常见的Eunotia物种。在刚果民主共和国南部的上加丹加省卢阿普拉河的一条小支流中，在2018年初采集的材料中也检测到了同一分类单元。我们可以将其识别为Eunotia enigmatica，最近在巴西东南部的水库中进行了描述。将刚果材料的瓣膜形态与巴西进行了比较。迷迭香很少被观察到，但也不罕见。在洛桑比亚河的两个样本中，该分类单元分别达到硅藻总组成的5.6％和5.4％。它不是在洛桑比拉河中观察到的唯一具有非洲和南美分布的物种。Encyonopsis frequenti S，也来自南美描述，比较常见的大肠杆菌enigmatica在乔波省收集的样本，最多时达到在Losambila河总硅藻成分的16.8％。然而，Encyonopsis frequenti s没有在样品中观察到E. enigmatica存在。同样适用于卢安普拉河支流（Eunconopsisquenti）的材料。在存在E. enigmatica的样品中未找到s 。