Ecological adaptations

Study of Planktonic forms of lakes of Mysore city

“Phytoplankton” is the collective name for the group of microscopic, aquatic photosynthetic organisms which are abundant in freshwater Lakes. During favourable conditions dense aggregations called “blooms” occurs which often causes fish kills or render the water unfit for any use. They have very high biological activity and are important is sustaining life in Lake waters. They are influenced by climatic changes and by variations in the physical and chemical constituents of the water and the uncontrolled conditions lead to water pollution.

The presence of phytoplankton in freshwater bodies is a widely accepted indicator of water quality. However, identification of the algal species, the knowledge of the algal cell number, or the physiological state of cells may also be important in providing a true picture of the water quality or trophic state.

The samples from both the lakes were collected in 30 mL vials. Few drops of Lugol’s iodine and few drops of 4% formaldehyde were added. The preserved samples were observed under microscope.

In the present study, lakes of Mysore district have been selected. Five different groups of phytoplankton applicable to water bodies have been analyzed. The smaller phytoplankton organisms can be readily identified. In order to facilitate identifications of the organisms at sea, an atlas of diatoms, dinoflagellates and myxophyceae of the region has been prepared.

1.      Phytoplankton were identified from Lake water belonging to four taxonomic assemblages: Cyanophyceae – Microcystis, Oscillatoria, etc.

2.      Chlorophyceae - Ulothrix, Oedogonium, Bulbochaetae, Pediastrum, Eudorina, Spirogyra, Closterium, Staurastrum and Cosmarium.

3.      Bascillariophyceae- Navicula, Synedra, Cymbella and Pinnularia

4.      Euglenophyta – Euglena and Phacus.