Effects of C/N ratios on growth and survival of white leg shrimp (Litopenaeus vannamei) by using monosaccharide as the carbohydrate supplement source in the biofloc based rearing system

Abstract

C/N ratio plays an important role in aquaculture system with biofloc technology application. The toxic nitrogen will be controlled through adding carbohydrates to water, which heterotrophic bacterial will be stimulated by the conversion of nitrogen in the bacterial biomass. However, most of the previous research used polysaccharide as carbohydrate supplement. The goal of this study is to explore the optimal C/N ratio of white leg shrimp Litopanaeus vannamei with using monosaccharide as carbohydrate supplement for best growth and survival. The experiment included three CN treatments with different C/N ratios at 10:1, 15:1, 20:1, and a control (no monosaccharide addition) with three replicates for each. The experimental tank volume was 120 liters, filled with water at a salinity of 22 psu. The stocking density was 60 larvae/tank. During the experiment, the water quality parameters found to be under the allowable limits in shrimp culture. After 45 days of the experiment, the findings of the experiment revealed that TAN and NO2 in CN treatments were both lower and significant statistically (p <0.05) relative to the control. At the end of the experiment, there were substantial differences in absolute growth, SGR, FCR were noted between treatment groups and control. Enhanced growth and survival were observed in C15 treatment. The results indicate that the CN15 ratio coupled with no water exchange is optimal for better survival and growth. Keywords: Biofloc, white leg shrimp (Litopenaeus vannamei), C/N ratios, monosaccharide, dextrose monohydrate, zero‐water exchange.