Cyanobacterial biodiversity from different freshwater ponds of Thanjavur, Tamilnadu (India).

ABSTRACT. Cyanobacterial biodiversity from different freshwater ponds of Thanjavur, Tamilnadu(India). Studies on the cyanobacterial biodiversity of 5 different freshwater ponds in and aroundThanjavur, Tamilnadu during summer month (June, 2004) has been made and compared their variationsamong five different ponds. In addition, certain physico-chemical parameters of pond waters such asdissolved oxygen, net productivity, pH, carbonate, bicarbonate, nitrate, nitrite, total phosphorus,inorganic phosphorus etc. were also analyzed and statistically compared with the cyanobacterialdiversity. Totally 39 species of 20 genera of cyanobacteria were recorded in all 5 different ponds.Only 6 species of cyanobacteria were identified in Pond 1 (Dabeerkulam), where a massive bloom ofMicrocystis aeruginosa was recorded, which had a significant effect in reducing the othercyanobacterial population. As many as five species namely Aphanothece microscopica, Synechocystisaquatilis, Merismopedia glauca, Oscillatoria limnetica and O. subbrevis were common in all theponds surveyed except in Pond 1.Key words. Biodiversity, ecosystem, cyanobacteria, Oscillatoria, Microcystis.RESUMEN. Biodiversidad de cianobacterias en diferentes charcas de agua dulce de Thanjavur,Tamilnadu (India). Se ha inventariado, y comparado entre sí, la biodiversidad de cianobacterias de 5charcas de agua dulce de Thanjavur, Tamilnadu (India); el estudio se llevó a cabo en junio de 2004.En paralelo, también se determinaron los valores de ciertos parámetros físico-químicos que podríanexplicar las variaciones en los valores de biodiversidad: oxígeno disuelto, productividad neta, pH,carbonato, bicarbonato, nitrato, nitrito, fósforo total, fósforo inorgánico, etc. Un total de 39 especiesde 20 géneros de cianobacterias se identificaron entre las 5 charcas. En la charca 1 (Dabeerkulam) sedetectaron 6 especies, pero cuando tuvo lugar una flor de agua de Microcystis aeruginosa las restantesespecies apenas se pudieron detectar. Cinco especies (Aphanothece microscopica, Synechocystisaquatilis, Merismopedia glauca, Oscillatoria limnetica y O. subbrevis fueron comunes en todas lascharcas con excepción de la número 1.Palabras clave. Biodiversidad, cianobacterias, ecosistema, Oscillatoria, Microcystis.