THE SELENASTRACEAE OF THE OLIGOTROPHIC LAKE STECHLIN (BRANDENBURG, GERMANY)

In the oligotrophic Lake Stechlin 14 species of the coccal green famil y Selenastraceae were observed. These species are living both in the p elagial as well in the benthic zone. Remarkable densities of Selenastr aceae were found in deep layer summer maxima about 20 m of the Lake St echlin. Monoraphidium lunare NYG. et al. has been found for the first time outside the locus classicus. A survey of the phytoplankton succes sion as well as some morphometric and nutritional characteristics of L ake Stechlin are given. Selected species are characterized by morpholo gical and ultrastructural diacritical features under culture condition s.