Interaction between physico-chemical attributes of water with different densities of Najas indica in ponds and its effect on shrimp (Penaeus monodon) growth performance at Bagerhat Region, Bangladesh

Abstract

Shrimp farmers in Bangladesh continue to hold differing views on the significance of Najas indica to their farming. Some shrimp farmers are worried it would harm their shrimp, while others aren’t. A solid scientific basis is still missing. Examining the effects of N. indica on shrimp farm’s (gher/pond) physicochemical parameters, survival rates, and growth rates of tiger shrimp (Penaeous monodon) was the main objective of this study. N. indica is an aquatic, submerged, invasive plant that typically found between 0 to 10 ppt salinities at shrimp farms in Bangladesh. The impacts of adding aquatic plants (N. indica) to the shrimp culture were studied, after three months to see how it affected water quality and shrimp output. Experimental setup includes a control (without N. indica) and two treatments (T1 and T2) with 20% and 40% N. indica were covered, respectively. Dissolved oxygen, pH, ammonia, total alkalinity, temperature, salinity, total dissolved solids, and conductivity were measured in this culture system. Temperature did not vary significantly (p < 0.05) across treatments, but dissolved oxygen did. Treatments T1 and T2 showed significant differences in water quality compared to the control pond, but not within the treatments (p < 0.05). Higher prawn survival rate (68.4%), average final weight (30.44 ± 0.77 g), and total production (832.8 ± 7.4 kg/ha) and lower feed conversion ratio (FCR; 1.15) were observed in T1 than control and T2. In conclusion it can be said that culture of shrimp with N. indica in a controlled manner reduces feed costs, increases shrimp growth, and it helps farmers to get benefits economically.

Keywords

• Najas indica
• Water quality
• Penaeous monodon
• Growth performance