The freshwater icthyofauna of Sri Lanka comprised 82 species; classified under 21 families and 44 species are endemic to the island. 28 species of Sri Lankan fish species are nationally threatened and nine species are globally threatened. The severe threat facing by endemic fish is habitat degradation and water pollution by increased human activities. Most of the endemic species found in Lowland wet zone which is densely populated and large area covered with Rubber and Tea plantations, which are harbored fascinating fresh water streams for the endemic endangered fish species. Also Sri Lanka has 24 introduced species of fresh water fishes.