EN
The present investigation are a continuation of the previous studies on the zooplanktonic organisms in the waters of the enclave situated in the borderland of Sredni and Wyspowy Beskids (the Carpathians). In particular, the streams in the valley of the River Krzczonowka and the waters of the Krzczonowka itself were studied from the point of view of the occurrence of the Paramecium aurelia species complex and other zooplankton. Recently, the waters in the region have shown a significant acidity in comparison with pH values noted in the sixties. So far, none of the species of the aurelia complex have been found in the streams as well as in the river. However, some predominant zooplanktonic organisms were registered. Previously (Komala 1998d) P. biaurelia was found in the Bogdanowka stream which flows into Krzczonowka, the main river of the valley.