TOLERANCE LEVEL OF CULTURED FRESHWATER FISHES TOWARDS BIOSURFACTANT

Objective: Biosurfactant at three different concentrations of 0.4%,0.5% and 0.8% were used and tested on 3 different cultured freshwater fish species, that is, Red Tilapia, Oreochromis sp.(cichlid), Puntius gonionotus (cyprinid) and Clarias sp. (catfish) to determine their tolerance level. Method & Materials: Each concentration was further diluted 10 X (10-1 to10-4) and subjected to 20 experimental fish of size 10-15g per duplicate. The fish were exposed in 100L aquarium for 7 days observation for any abnormalities and/or mortality, with daily monitoring of the water quality parameters especially temperature, DO, pH and ammonia. A group of 20 fish of each species was kept untreated as control Results & Conclusion: When compared with the control untreated fish, the mortality rates of fishes treated with biosurfactant were slightly high but insignificant (p<0.05). The mortality was possibly due to the poor water quality as the recorded ammonia level fluctuated daily, ranging from 1.5 to 2.5 mg/l. In conclusion, biosurfactant at concentrations of 0.4%, 0.5% and 0.8% are safe to be used in the three species of fish tested

کلیدواژه ها:

biosurfactant ، red tilapia ، P. gonionotus ، Clarias sp. tolerance level ، mortality ، water quality