Distribution pattern of freshwater cyanobacteria in Kaiga region of Western Ghats of Karnataka

This study deals with the identification of 59 cyanobacterial species belonging to 27 genera from different freshwater habitats of Kaiga in Uttara Kannada district of Karnataka during the period from June 2009 to May 2011. Samplings were made during pre-monsoon; monsoon and post-monsoon sampling have been carried out for the duration of 2 years. The study deals with the occurrence of cyanobacterial species in five different aquatic habitats in Kaiga region, with respect to a change in the physico-chemical properties of water. The cyanobacterial diversity is maximum in monsoon season compared to post-monsoon; it was least during pre-monsoon. Among cyanobacteria non-heterocystous filamentous forms were dominant followed by unicellular forms, whereas heterocystous forms were least in number. It was also found that the physicho-chemical properties of water have the influence on the richness of cyanobacterial community. This study indicates the maximum occurrence and abundance of Chroococaceae (23.73%) and Phormidaceae (18.64%) members in all the sites, whereas Stigonemataceae (1.7%) shows very less occurrence. Among the cyanobacteria identified non-heterocystous filamentous forms were dominant followed by unicellular forms; whereas heterocystous forms were least in number.