Factors influencing amphibian population at Cauvery river banks of Nagappattinam District, Tamil Nadu, Southern India
The amphibians are the most sensitive animals to environmental changes as they are in intimate contact with many components of the natural surroundings. They may signal environmental degradations earlier than most other organisms and hence serve as critical bio-indicators of the ecosystem. Most of the organisms living in water bodies which are sensitive to changes in their environment. The present study was carried out at Cauvery River banks of Nagai District from April 2010 to June 2010 with the objective to register the water quality, diversity and abundance of amphibian fauna in the old and new Cauvery regions with special reference to the physico chemical parameters. Several physicochemical or biological factors could act as stressors and adversely affect the aquatic animal growth and reproduction. Hence, regular monitoring of physicochemical and biological water quality parameters is essential to determine the status of aquatic medium with reference to aquatic animal management. Water samples were analyzed by standard procedures of APHA, 1995. The frog population was calculated as number per hectare. Statistical analyses were performed by using window based statistical packages mainly, Microsoft EXCEL, Minitab and SPSS. To understand the relationships between the frog populations with physico chemical characteristics of water was analysed through Pearson’s correlation. Present survey revealed that only one species was recorded in the study area with the highest abundance in April 2010 in Cauvery River than old Cauvery River. The present study proved that, if the water quality is altered, the density of Euphlyctis cyanophlyctis population will also suffered a lot and it leads to imbalance in the ecosystem. This study concludes that Euphlyctis cyanophlyctis could be habitat specific, which could be influenced by water quality. So far as the amphibian diversity is concerned only one species of Euphlyctis cyanophlyctis was recorded. An overall water quality influence on amphibian density, distribution and abundance was evidenced from the present study and needs further investigation.
Amphibian Diversity, Cauvery River, Nagai District, Water quality.