Abstract:
The study stomach content analysis of "kasau" fish from Siak river has been conducted from July to
October 2008. Samples of fishes were taken at three sites along Siak river namely in Leighton bridge, village
Tebing Tinggi Okura and the village Perawang. The Collection of the fishes from those three sites conducted
every month, by census and stratified sampling methods. The stomach content analysis show that their food
consist of Cyanophyceae, Chlorophyceae, Bacillariophyceae, Xanthophyceae, Roti fera and Cladocera. Base
on the kind of food they consumed, the fishes classified as omnivorous with the dominant were Cyanophyceae
and Chio rophyceae.The value of Index of Preponderance (IP) Cyanophyceae was over 40% and Chlorophyceae
was approach 40 %. The class of Cyanophy ceae was dominated by genus Dactylococopsis, while the class
of Chloro phyceae was dominated by the genus Closterium. Most of the plankton genera found in the stomach
did not find in the Siak waters. Probably the fish found their food from the swamp around th Siak river.
