Effect of carbon and nitrogen ratio (C:N) manipulation on the production performance and immunity of Pacific white shrimpLitopenaeus vannamei(Boone, 1931) in a biofloc‐based rearing system

Abstract

A 16-week indoor culture trial was conducted to evaluate the effect of varying C:N ratio on growth performance, physico-chemical parameters, microbial dynamics, feed utilization, and immunological parameters. The experiment comprised of five biofloc treatment groups (with varying C:N ratio 5:1, 10:1, 15:1, 20:1) and a control with three replicates each, having 100 nos/m 3 as stocking density in 500 L tanks with constant aeration. The C:N ratios of the treatments were manipulated using molasses as an organic carbon source whereas there was no carbon source added in control. The water quality parameters monitored throughout the experiment were found to be within permissible limits in shrimp culture. At the end of the experiment, it was observed that there were significant differences between the treatment groups and the control regarding absolute growth, SGR, FCR, PER, and FER.Furthermore, a considerable difference in immunological parameters, namely, THC, phagocytosis, and PO activity (17.5 × 10 6 cells per ml, 43.5%, 0.112 Units min −1 mg min −1 ), was recorded among the treatments compared to that of the control groups (6.2 × 10 6 cells per ml, 31.5%, 0.051 Units min −1 mg min −1 ) respectively. Enhanced growth and survival with substantial disease resistance were recorded in C15 treatment. The results indicate that the CN15 ratio coupled with minimal water exchange is optimal for improved survival, growth, and immune activity. K E Y W O R D S C:N ratio, molasses, water quality, zero-water exchange 1 | INTRODUCTION Availability of specific pathogen-free shrimp has resulted in increased shrimp farming in terms of culture as well as production. The choice of Litopenaeus vannamei over Penaeus monodon is primarily due to enhanced production, SPF availability, higher yield after processing, and higher market demand. Of late, biofloc technology (BFT) has gained momentum and positive response in shrimp and tilapia farming. In India, farmed shrimp production increased from <1 lakh tonnes in 2009 to 3.5 lakh tonnes in 2014. In 2016-2017, the production was over 5 lakh tonnes, accounting for 38% in quantity and 64.5% in value (Rs. 24,426 crores) of the total Indian seafood export worth 5.78 billion dollars (Rs. 37,870 crores) (MPEDA, 2017). The expanding culture system influences water quality and environmental factors. Due to intensification with higher stocking densities, there isHighlights Growth, physico-chemical, and microbiological parameters were substantially higher in carbon and nitrogen (CN) ratio treatments compared to control. Optimization of C:N ratio in L. vannamei culture revealed an optimum ratio of 15 to be ideal for a biofloc-based system. Challenge study revealed higher mortality in control compared to CN-treated groups when challenged with the pathogen Vibrio parahaemolyticus (MTCC 451). Carbon supplementation appears to influence heterotrophic bacteria and provides immunity and protective response under BFT-based rearing. Immune responses like THC, phagocytic activity, and proPhenoloxidase activity we...

Nutritious ponds : valorising waste using natural production

“…In this study, total C and N input and C:N input were similar in all tanks. But other studies show more water column flocculated matter develops at increasing total C input and increasing C:N system input up to 20, while shrimp protein retention shows an optimum at C:N system input of 15 (Panigrahi et al, 2019). The C:N input in this experiment was 10 for all tanks, which is not high.…”

“…In consequence, a well-balanced food web will develop, delivering natural food to the culture animal. Developing such a lower-cost and more ecological-based production system has been given more and more attention in research (Joffre and Verdegem, 2019, Hari et al, 2004, Panigrahi et al, 2019, Anand et al, 2015, Panigrahi et al, 2018. Natural food, such as biofloc and periphyton, are known to contribute additional energy and protein to the diet of shrimp in ponds (Chapter 4, De Schryver et al, 2008, Avnimelech, 2009, Wasielesky Jr et al, 2006, Asaduzzaman et al, 2010.…”

Effect of Probiotics and Carbon Sources on Growth Performance and Survival of Indian White Shrimp (Fenneropenaeus Indicus) Under Biofloc Technology

“…This resulted in a negative growth rate. Many studies have shown that growing of shrimp species such as L. vannamei in biofloc system can improve shrimp growth as compared to clear water (Khanjani et al, 2016 andPanigrahi et al, 2018). Also, the results indicated that the abnormalities found in shrimp fed with biofloc with corn flour as carbon source possibly correspond with the shrimp cannibalistic behavior.…”

“…In order to provide a carbon source for heterotrophic bacteria, carbohydrate can be directly added to the cultured water or incorporated into the artificial feed. To promote the bacterial growth, carbohydrate addition is carried out to adjust the C/N ratio of the system to 10 or more (Azim et al, 2007; Cavalli, and Wasielesky, 2012and Panigrahi et al, 2018. The availability of carbon thus allows more efficient use of nitrogen as the excreted nitrogen will be converted in bacterial biomass, which is further consumed by the cultured species.…”

Effects of Addition of Sucrose and Probiotics on Whiteleg Shrimp Litopenaeus vannamei Postlarvae Performance, Water Quality, and Microbial Community

“…These two aspects (C:N ratio and probiotics) should mediate the effects of biofloc technology on the growth of shrimp (Panigrahi et al. 2018a, 2018b; Hostins et al. ).…”