Nepal is rich in fish diversity. The richness and uniqueness of the fresh water fishes of Nepal are due to different topographic and climatic conditions of the country within a short distance of elevation from plain Terai to high altitude mountains as well as tropical to alpine climatic conditions. Nepal is rich in natural resources and it is second richest having highly potential in term of water resources .There are more than 6000 rivers and rivulets including big and small . There are three major river systems in Nepal namely Koshi, Gandaki and Karnali which along with other rivers and scores of lakes (5358) and reservoirs are the habitat of 230 native species of fish from different climatic zones. There are 9 species of Crabs, 3 species of Prawns, 50 species of Mollusks, 53 species of Frogs, 47 species of Reptiles, 193 species of Water birds and 84 species of Aquatic plants. Water resources are abundant throughout the country in the form of snow covers, rivers and streams, lakes, marginal swamps and groundwater.