Distribution of Corbicula Fluminea at Gunung Reng River, Kelantan.

Corbicula fluminea (Bivalvia: Corbiculidae), locally known as “Etak” is a species that have been the subject of much research due to its capacity to spread over large areas and become the most important competitor with native species of freshwater bivalves and potentially causing ecological imbalance. Late research done, the distribution and density of C. fluminea in this study was conducted in Sg. Pergau at Gunung Reng, because since the observation show that there were populations of C. fluminea there. To study the density and distribution of C. fluminea, the numbers, weight and the measurement of C. fluminea was identified. In addition, water quality and type of substrate was also studied to identify the habitat characteristics that affect the density and distribution of this species. As there was no documentation of distribution and density of C. fluminea in Sg. Kelantan, it would be difficult to compare the density and distribution of Etak in the others river in Kelantan. As the finding shows that, the density and distribution of C. fluminea at Gunung Reng was not affected by water quality used (conductivity, pH, turbidity, salinity, temperature, DO and nitrate). The most important factor that give the huge effect toward both distribution and density of Etak is substrate composition. In this study shows that the best substrate for C. fluminea ranged from 0.25mm and 0.71mm which represent sand (sand-coarse and sand-fine).