Ref ID : 6626
Boris Lohlein; Seasonal dynamics of aufwuchs Naididae (Oligochaeta) on Phragmites australis in a eutrophic lake. Hydrobiologia 334:115-123, 1996
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The Oligochaeta and Aphanoneura in the aufwuchs on Phragmites australis in a eutrophic hardwater lake were studied at two sites over a period of one year, in order to elucidate the structure and dynamics of this assemblage. The naidids Chaetogaster diastrophus, Nais spp., and Stylaria lacustris dominated the assemblage at any season. At both sites these taxa showed the same distinct pattern of successive populations maxima in spring and summer: Chaetogaster diastrophus reached its peak density first, followed by Nais species, and eventually by Stylaria lacustris. Differences in temporal dynamics between sites were small apart from a second Stylaria maximum which was only observed at one site. Total naidid densities reached peak values of 3.8 individuals per cm2 reed stem surface area. With mean individual biomass of 2.2 µg dry mass for Chaetogaster diastrophus, 13.3 µg for Nais, and 86 µg for Stylaria lacustris, respectively, maximum total naidid biomass on reed stems was 44 µg dry mass per cm2. The biomass peak occurred later than that of total naidid density because in summer larger naidids dominated the assemblage. The observed succession appears to be consistent with seasonal changes in periphytic algal communities on the reed stems.