A comparison of benthic meiofaunal communities in the oldest European lake

Abstract

The comparison of isolated stable habitats, that share major ecological parameters and organism groups, generates valuable knowledge about ecology and evolution. In this study we want to identify the most suitable habitat and organisms for comparisons. For this, we needed to study the effects of seasonality, habitat variability and diversity. Therefore, we studied the benthic meiofaunal communities in the sediment and hard substrates of Lake Ohrid’s littoral and profundal sediments as well as littoral rotifers collected monthly and seasonally between 2000 and 2010. Our results showed that, among the over two million meiobenthic organisms per square meter, nematodes dominated the profundal (mean proportion: 91%) and littoral (mean proportion: 87%) sediments; whereas, rotifers were the most abundant group in littoral periphyton (mean proportion: 64%). The community composition was very typical of each habitat-type, homogeneous in the profundal and more heterogenous in the littoral. Rotifer communities were only significantly less diverse and abundant in winter. Thus, a comparison of ancient lake nematodes living in the deep profundal is potentially quite valuable. However, littoral communities are less stable in terms of seasonality and heterogeneity.