The present research has been carried out in different broad aspects viz. bio-ecological parameter analysis of freshwater streams and Biographical distributional status of the endemic stream-fishes in palani hills of southern India. The physical and chemical parameters were taken from the streams of study area and analyzed with regard to freshwater stream fishes, for example, Devariomalabaricus (Devario), Punitus denisonii, Punitus dorsalis, Horalabiosa joshuai may be the most threatened group of vertebrates on earth after amphibians and the global extinction rate of fishes was believed to be in excess of higher vertebrates, However, conservatory measures to mitigate the impact of the pressures have not only been slow but also inadequate and as a result many of the aquatic fish species decline rapidly. The main causes behind the loss of biodiversity in freshwater streams were found with habitat degradation and water depth decline, exotic species introduction, water diversions, pollution, and seasonal change impacts. The diversity and system of the genus cyprinidae form genus currently and the genus includes at least eleven species, all endemic to fresh water system of palani hills of south India. While these species found commonly in south India and were frequently used as a food sources, little was known about the morphological diversity within between species and nothing was known regarding intraspecific genetic diversity (or) species relationship. This study provided information of the physical chemical and morphological properties, including morph metrics and distributional variation that have been reported in Punitius species, suggesting significant diversity among the selected species. The clearly the genus warrant more through bio-geographic sampling and examination of morphological data or analysis to reveal the natural lineage exist in this research work. This study would be useful in future to understand the phylogenetic position and biographical distribution of fresh water stream fishes in palani hills of Tamilnadu, South India

Key Words: Bio-ecological studies, Fresh water fishes, diversity conservation, distribution pattern, Palani hills.