PUB - Publikationen an der Universität Bielefeld

Recent studies on meiofaunal and nematode communities have focused on soft sediments in streams, lakes and marine environments. Despite a large number of studies dealing with periphyton, meiofaunal and nematode communities on littoral hard substrates in lakes have not yet been investigated in detail. Therefore, epilithic communities with special emphasis on nematode species composition of 17 Swedish lakes differing greatly in size, depth, trophic status and epilithic biomass were analysed. Nematode abundance ranged from 2.3 to 161.5 Ind cm-2, and the abundance of nematodes relative to total meiofauna ranged from 20 to 77% (mean 53%). Fifty-eight nematode species were identified; species number varied from 8 to 34 species per lake. The dominant species were Rhabdolaimus aquaticus (de Man, 1880), Punctodora ratzeburgensis (Filipjev, 1903), Eumonhystera dispar (Bastian, 1865) and Crocodorylaimus flavomaculatus (Linstow, 1876). Deposit-feeders dominated (71% of total fauna), followed by suction-feeders (14%), epistrate-feeders (12%) and chewers (3%). Of 3624 nematodes examined, 54% were juveniles, 35% females, 6% males and 5% gravid females. Multivariate analysis of the nematode species composition revealed significant differences in the community structures among lakes. This is the first study to show that meiofauna is a numerically abundant group within littoral periphyton communities in lakes with nematodes representing the dominant group.