Paper Title
ASSESSMENT OF THE GROWTH OFINDIAN MAJOR CARP ROHU (LABEOROHITA) WITH TILAPIA (OREOCHROMIS NILOTICUS)IN THE CAGE CULTURE SYSTEM OF BANGLADESH

Abstract
Abstract - The study was conducted over a period of 90 days from August to November 2022 in the Barguna district of Bangladesh to assess the growth and production performance of Rohu(Labeorohita) in cage culture with tilapia. The experiment was designed with three treatments namely T1 (only tilapia-100%), T2 (tilapia-80% and rohu-20%) and T3 (tilapia-60% and rohu-40%) respectively each having three replications. The stocking density was 50/m3.The floating feed contained 30% protein supplied twice a day at the rate of 5-3% of their body weight.Water quality parameters were recorded every fifteen-day interval throughout the culture period. Physico-chemical parameters, such as water temperature (°C), pH, dissolved oxygen (mg/l), ammonia (mg/l), nitrite (mg/l) and alkalinity (mg/l) hardness (mg/l), salinity (ppt) were measured. Water quality parameters were within the suitable range for fish culture. At the end of the culture period higher weight gain of Tilapia (257g) was recorded in T3 followed by T1(245g) and T2(250g) and the lowest weight gain of Rohu (90.17g) was observed T3.The survival rate of tilapia ranges from 94.2 to 96.20% and rohu from 90.15 to 90.50%. There were no significant differences (P>0.05) in the survival rate of tilapia and Rohu. The weight gain, % weight gain, and SGR of tilapia and rohu were found higher in T2, followed by T3, whereas tilapia showed higher growth in T3 and followed by T2 and T1.Significantly higher (p>0.05)total production of fish was observed in T1(122.46 kg), followed by T2(111.16 kg) and T3(98.463kg). The BCR was higher in T1 (1.67), followed by T2 (1.62) and T3 (1.55). The result of the study revealed that the culture of Rohu with Tilapia in the cage is not suitable because the growth performance of Rohu was very poor. It was observed that during feeding Tilapia showed very aggressive behavior due to the presence of their sharp spine. As a result, Rohu was not able to intake a sufficient amount of feed. So, it is not recommended to culture Indian major carp rohu with tilapia in the cages. Keywords - Tilapia, Rohu, Cage Culture, Production.