ABSTRAKT

Abundant vegetation of the limnophilous species Limnothrix redeckei (Van Goor) Meffert was recorded in the plankton of the plain unregulated Barnaulka River downstream in 2002-2003 at the end of summer-autumn and at the beginning of winter low-water period. A decline in both the water level and external water exchange intensity caused the vegetative abundance. Evidently, the dynamics of average values of cell and trichome volume, and of the number of cells in L. redeckei trichome were determined by different combinations of cell growth and fission rates together with external water exchange. Trichomes of L. redeckei with completely or partially absent aerotopes differed from Pseudanabaena limnetica (Lemm.) Anagn. et Komárek. This doesn't coincide with Whitton's (2002) observations and his assumption concerning the identity of these species.