Taxonomy is the science of classification of organisms including nomenclature. Taxonomy provides a picture of existing biodiversity on the earth along with information needed for entire biology. It provides more information needed for reconstruction of phytogeny of life and ordering systems or classification. It also reveals numerous interesting evolutionary phenomenons and makes them available for casual study. Fish constitutes almost half of the total number of vertebrates in the world living in almost all conceivable aquatic habitats. India is one of the mega-biodiversity countries in the world and occupies the ninth position in terms of freshwater mega-biodiversityt. (jacket)