Abstract

Coastal wetlands are physiologically unique from freshwater and marine water environments. They support the growth of both marine and freshwater organisms with affluent diversity. In this study, abundance and diversity of cyanobacteria from the coastal wetlands of Kanyakumari District (Tamil Nadu) in India was studied. Water samples were collected from ten different sampling sites during the month of January 2010 to March 2010. Totally 17 morphologically different cyanobacteria were identified by microscopic examinations and culture-dependent processes. Both unicellular and filamentous cyanobacteria like Microcystis flos-aquae, Microcystis lamelliformis, Gloeocapsa sp, Aphanocapsa sp, Aphanothece sp and Synechocystis sp. Oscillatoria earlei, Oscillatoria pseudogeminata, Oscillatoria tenuis, Oscillatoria amoena, Phormidium fragile, Phormidium retzii, Phormidium sp., Lyngbya sp, Symploca sp. Microchaete sp. and Spirulina subtilissima were identified. In addition, the species richness index was ranging from 0.779 to 1.097 in the samples collected in month of February (S8- Muttam). Substantial diversity was also detected in different sampling regions, Shannon-Wiener’s (H^!) diversity index of cyanobacterial population ranged from 0.423 to 0.788. In our findings, all the identified cyanobacteria were belonging to non heterocystous forms.

Key words: Cyanobacteria, coastal wetland, Oscillatoriaceae, Chroococcaceae.