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Free keywords:
cladocera; sediment analysis; lake trophy; bioindication
Abstract:
The cladoceran faunas from 13 northern German lakes (the Plon district) of different trophic levels were analysed using the bosminid and chydorid remains in the surficial sediment as an integrated sample of the total lake fauna. In the dimictic lakes, a shift occurred in the composition of planktonic Cladocera from Bosmina coregoni, including morphs with a mucro, to predominance of Chydorus sphaericus and Bosmina c. thersites as trophic state increased. In the benthic Cladocera (Chydoridae), there was a decrease in species diversity, in the percentages of phytophilous species and in the portion of species that are typical of 'clear water lakes', but there was an increase both in the number of mud dwellers and species that are typical of 'polluted lakes'. No positive correlation was found between mean depth of the lakes and the planktonic/littoral ratio
