FEATURES OF THE SEASONAL DYNAMICS OF PHYTOPLANKTON AT THE LEFT BANK OF THE VOLGA REACH OF KUIBYSHEV RESERVOIR (REPUBLIC OF TATARSTAN, RF)

Biocenosis of shallow waters of lowland reservoirs lives in various habitat regimes and are characterized by a special structural and functional organization. To fully elucidate these features, it is necessary to research several hydrologically different areas simultaneously. This study was conducted to evaluate the effect of seasonal dynamics on the phytoplankton community of the Volga reach of the Kuibyshev reservoir near the left bank. During the observation period, 112 taxa were found in the phytoplankton of the studied site. The greatest number of taxa were identified from the groups of diatoms (44%) and green (28%) algae. Some other less diverse groups are blue-green (16%), Chrysophyta (6%), cryptophyta and dinophyta (3%), etc. Cosmopolitan and planktonic species of algae prevail in terms of environmentally-geographical characteristics. Concerning halobility, most species are indifferent, and in terms of pH, the most common are the indifferent alkaliphile + alkalibiontic algae. The total abundance and biomass of planktonic algae range 8.49-1661.09 mln.cl./l and 10.28 -114.11 mg/l respectively. Some important dominant species are blue-green algae Microcystis aeruginosa f. flos-aquae, Aphanizomenon flos-aquae, Anabaena flos-aquae, Anabaena scheremetievi, Aulacoseira italica, Navicula sp., Carteria globosa, Chlamydomonas sp., Pandorina morum, Scenedesmus guadricauda. Seasonal dynamics of phytoplankton have two peaks of abundance and biomass which are at the end of the first decade of July and in the second decade of August. Both maxima are due to the massive development of blue-green algae, which causes water to “bloom”. The phytoplankton of the investigated section of the Kuibyshev reservoir is dominated by β-mesosaprobic organisms.

Algas planctônicas flageladas e cocoides verdes de um lago no Parque Beija-Flor, Goiânia, GO, Brasil

RESUMO Os parques públicos de Goiânia apresentam importância socioambiental para a cidade, no entanto pouco se conhece sobre a sua qualidade e biodiversidade aquática. O presente estudo é focado nas Chlorophyceae e Trebouxiophyceae (Chlorophyta) em um lago de parque urbano localizado no município de Goiânia, GO, durante um curto período de chuva e de seca. As coletas foram realizadas semanalmente durante agosto de 2007 e janeiro de 2008, em três estações de amostragem, de acordo com as técnicas usuais para análises florísticas. Foram identificados 25 táxons infragenéricos: 16 Sphaeropleales, seis Chlorellales, um Chlamydomonales, um Chlorococcales e um táxon de Trebouxiophyceae de posição incerta. Pandorina morum, Lacunastrum gracillimum, Desmodesmus intermedius var. acutispinus e Pachycladella komarekii são registradas pela primeira vez para o Estado de Goiás.

New and rare species of Volvocaceae (Chlorophyta) in the Polish phycoflora

Seven species of Volvocaceae were recorded in the lower Vistula River and its oxbow lakes, including <em>Pleodorina californica</em> for the first time in Poland. Three species – <em>Eudorina cylindrica</em>, <em>E. illinoisensis</em> and <em>E. unicocca</em> – were found in the Polish Vistula River in the 1960s and 1970s, as well as at present. They are rare species in the Polish aquatic ecosystems. Three species are common both in the oxbow lakes and in the Vistula River: <em>Eudorina elegans</em>, <em>Pandorina morum</em> and <em>Volvox aureus</em>. New and rare Volvocaceae species were described in terms of morphology and ecology; also photographic documentation (light microscope microphotographs) was completed.