Catfish (Clarias sp.) is a freshwater fish that is widely cultivated in almost all of Indonesia. It is an important commodity with good market prospects. Some of the benefits of catfish is that it has a high nutrient content, economic value, fast growth and easy maintenance. One problem for catfish farmers is that not all regions have good freshwater resources. Likantibioe the coastal areas and small islands in the middle of the seas with minimal freshwater resources. The water quality in the area is usually poor due to salty or brackish ground water.
Salty or brackish groundwater is closely related to salinity. Salinity is one of the parameters of water quality that directly affects fish metabolism, especially the osmoregulation process. Therefore, by giving different salinity treatment in aquaculture activities, it is estimated that it can affect the growth rate, survival rate and feed conversion ratio (FCR) of fish. Therefore, this research was conducted to find a solution related to the problem of fresh water crisis that is feasible for catfish farming activities. By using 7-9 cm catfish, this study established four treatments by changing salinity levels in aquaculture water: salinity 0 ppt (P0), 3 ppt (P1), 6 ppt (P2) and 9 ppt (P3).
The results of the study showed significant differences or influences. For 30 days, the average growth rate at P0 was 2.524 grams; P1 of 1.572 grams; P2 of 1.783 grams and P3 of 3.085 grams. The growth rate is an increase in the length and weight of fish over a period of time. Fish growth will occur when there is excess energy from the feed protein needed for maintenance and body activity used for growth. The results showed that the highest growth rate was from P3. Higher levels of salinity contained in P3 (9 ppt) made fish more active and the osmoregulation process continues to occur in the body of the fish. The tendency of fish to be active can make them eat again and adjust the environment, and physiological processes in the fish work normal again.
Regarding fish survival testing, different salinity treatments have no effect on this because the data generated shows 100% overall value. According to Muhammad (2006), catfish are stenohaline fish, which are organisms with a high ability to adapt to salinity, so the fish endurance is stronger and influences optimal survival. Then for the feed conversion ratio (FCR) which is the ratio between the amount of feed consumed by fish and the weight gain of the fish produced. Based on the results of the study for 30 days of cultivation, the average FCR data for P0 was 0.891; P1 was 1.142; P2 was 1.074 and P3 was 0.765. The lower the value of the feed conversion ratio, the better for commercial farming activities, because the feed needed by fish is lower but the growth of fish produced is more optimal. The lowest feed conversion ratio results in the treatment P3 (9 ppt). Salinity is needed by fish to regulate fluid balance which can stimulate faster growth. Energy derived from food can be fully utilized to increase fish growth, so the physiological process runs normally. As for the highest feed conversion ratio was from the treatments P1 (3ppt) and P2 (6ppt). High feed conversion was caused by undigested feed or less preferred types of feed. So it causes high ammonia value in the waters and tends to make catfish unable to utilize feed properly.
Based on research that has been done, it can be concluded that the effect of different salinity (0ppt, 3ppt, 6ppt, 9ppt) can affect the growth rate, survival and feed conversion ratio in catfish. The highest growth rate results were found in the treatment P3 (9ppt), which is 3.085 grams. The survival value obtained for all treatments is 100%. And the lowest feed conversion ratio was found in the treatment P3 (9ppt) of 0.765.
Based on research that has been done, it can be concluded that the effect of different salinity (0ppt, 3ppt, 6ppt, 9ppt) can affect the growth rate, survival and feed conversion ratio in catfish. The highest growth rate results were found in the treatment P3 (9ppt), which is 3.085 grams. The survival value obtained for all treatments is 100%. And the lowest feed conversion ratio was found in the treatment P3 (9ppt) of 0.765.
Author: Prayogo
References: Prananingtyas D, Prayogo dan B.S Rahardja. Effect of Different Salinity Level within Water Against Growth Rate, Survival Rate (FCR) of Catfish (Clarias sp.). IOP Conf. Series: Earth and Environmental Science 236 (2019) 012035.
References: Prananingtyas D, Prayogo dan B.S Rahardja. Effect of Different Salinity Level within Water Against Growth Rate, Survival Rate (FCR) of Catfish (Clarias sp.). IOP Conf. Series: Earth and Environmental Science 236 (2019) 012035.
