Effect of Different Carbon Sources on bioflocs formation effect on water quality and production in White Shrimp Culture System Litopenaeus vannamei

Abstract

Total ammonia nitrogen (TAN) is one issue on White shrimp cultivation. To reduce the TAN levels in order to remain within the limits specified in the cultivation process, the addition of organic carbon sources to improve the C / N ratio which aims to encourage the growth of heterotrophic bacteria. The study consisted of two phases. Phase one aims to determine the decrease in the concentration of TAN. This study uses a completely randomized design with four treatments and four reaply such as the addition of a carbon source (A) molasses; (B) tapioca; (C) rice bran; (D) the use of cassava by product with C/N ratio of 10, 15 and 20. Parameters is observed as a decrease in the concentration of TAN and DO, pH and temperature. Data were statistically analyzed by one-way analysis of variance (ANOVA) using Minitab software (version 16.0) at the 95% confidence interval (P <0,05).The measurements of TAN with different C/N ratios giving different values where the C/N ratio of 20 has effect not significantly different from C/N ratio of 15, but has a significantly different effect with the C/N ratio of 10 in all treatments of carbon sources after 24 hours. Phase two study aimed to determine the effect of carbon sources on bioflocs profile, water quality parameters and growth performance of White shrimp. The study consisted of 4 treatments such as the addition of a carbon source (A) molasses; (B) tapioca; (C) rice bran; (D) cassava by product and without carbon, use of C/N ratio of 15 and four reaply. Parameter of water quality are TAN, nitrite, nitrate and ammonia. Bioflocs profile observed is identification of bacteria, Vibrio bacterial counts and the total number of bacteria in the water and shrimp intestine. Production parameters observed is specific growth rate, feed conversion, survival rates and average weights of White shrimp. Water quality parameters, especially TAN, nitrite and ammonia decreased at the end of maintenance period. Results of profile bioflocs found some microorganisms such as worms, phytoplankton and zooplankton. Genus Bacillus sp. was found in all treatments of carbon sources. Highest total number of bacteria present in molasses treatment (water and intestinal shrimp). Vibrio bacteria counts are highest in the no-carbon treatment (water and shrimp intestine). Vibrio bacteria counts are highest in the no-carbon treatment (Water and shrimp intestine). Feed conversion on treatment without carbon carbon (1.67 ± 0.10) were significantly different with the treatment of tapioca (1.41 ± 0.13). White shrimp survival rate during the maintenance treatment without carbon (84.17 ± 3.20%) was lower in all treatments and were significantly different with cassava by product treatment (92.50% ± 5.00).