MACROZOOBENTHOS OF A COASTAL LAKE IN SOUTHERN BRAZIL

Benthos of a coastal lake in southern Brazil, Lake Emboaba, was collec ted in summer and winter 1989/90 to describe the community and its spa tial distribution, and to identify potential seasonal differences in c omposition and abundance. A total of 19 randomly distributed sites wer e sampled (van-Veen grab, 4 replicates, 500 mu m) on two dates. Total mean densities of the heterogeneously distributed benthos were low wit h 921.3 ind./m(2) and 640.3 ind./m(2) in summer and winter, respective ly. Neither density nor composition differed significantly between sea sons. Insecta, mainly Chironomidae, were most abundant, followed by Cr ustacea, mainly Synelobus stanfordi (Tanaidae), and Oligochaeta. Clust er analyses, linked subsequently by a nodal analysis, revealed the pre sence of three benthic zones (centre, margin, marsh), distinguished by benthos density and composition, including differential species and s pecies assemblages. This result is remarkable as the shallow lakes of Brazil's coastal plains are exposed to permanently blowing north-east winds.