Diversity of freshwater fishes at lower stream of Tuaran river, Sabah / Nurul Nadzirah Yusman

Sabah is rich with freshwater fishes and about 168 species can be found. Many localized studies of freshwater fishes focusing on areas such as Lahad Datu, Kota Marudu, Ranau and Kinabatangan had been done since the past few years, nevertheless, no further comprehensive studies have been made. When narrowing down the scope in Tuaran, the available information on the fish fauna at Tuaran River is only limited to locations of tagal and a few human activities such as sand mining have posed many threats to the aquatic living. This made it very difficult to gain any information related to the fish fauna available. The study was conducted with the purposes to provide morphological data and hence determine the diversity of freshwater fishes found at lower stream of Tuaran River, Sabah. All of the fish samples were captured by using cast nets along three selected stations. Throughout this study, a total of 225 individuals of 15 species and 12 families were captured which the family Cyprinidae gave the highest percentage. All of the fish specimens were measured and identified and the data were recorded for future references on the morphological data. The diversity index of the freshwater fishes ranged from 1.67 to 1.85. An exotic species Oxyeleotris marmorata (Ketutu) which is the top five most expensive fish in Malaysia was also captured during this study which shows that the lower stream of the Tuaran River might be the potential habitat for this exotic species along with other valuable species such as Pangasius hypopthalmus (Patin) and Tilapia sp..