Effects of carbohydrate sources on a biofloc nursery system for whiteleg shrimp (Litopenaeus vannamei)

Tran Huu Tinh,Tom Koppenol,Tran Ngoc Hai,Johan A.J Verreth,Marc C.J Verdegem

doi:10.1016/j.aquaculture.2020.735795

Tran Huu Tinh, Tom Koppenol + Show 3 more

Open Access

https://doi.org/10.1016/j.aquaculture.2020.735795

Copy DOI

Abstract

In biofloc technology carbohydrate is added to stimulate the biofloc growth, the latter helps to improve water quality, reduce the need for water exchange and may serve as natural shrimp feed. The large diversity among possible carbohydrate sources makes the selection of a suitable carbohydrate difficult. This study investigated how corn starch addition compared to molasses addition affected water quality, biofloc and periphyton proximate composition, shrimp production parameters, diurnal fluctuations and distribution of carbon and nitrogen in whiteleg shrimp (Litopenaeus vannamei) culture system. The results showed that both corn starch and molasses addition treatments resulted in low ammonium nitrogen levels in the water. The total suspended solids and volatile suspended solids in both treatments increased over time and were not significantly different among treatments. The protein content in the dry matter of the biofloc varied from 34% to 48%, being higher in the molasses treatment. The same was observed for the protein content in the dry matter of the periphyton which ranged between 16% and 26%. The corn starch treatment resulted in significantly higher shrimp growth rate, production, average body weight, and lower FCR compared to molasses addition. Water quality was stable on a daily basis, but changed over the weeks. Carbon and nitrogen accumulations in the system were not significantly different among treatments.

Highlights

The role of aquaculture in fish supply for human consumption has been increasing since the 1980s (FAO, 2018)
This research aimed at comparing the effects of different CHO on water quality, biofloc and periphyton proximate composition, shrimp production parameters, the diurnal fluctuation of water quality parameters following the addition of feed and CHO, and quantifying the accumulation of nutrients in different compartments of the biofloc shrimp culture
Shrimp survival rate was above 90% in both treatments, and significantly higher in the corn starch treatment (P < .05)

Summary

Introduction

The role of aquaculture in fish supply for human consumption has been increasing since the 1980s (FAO, 2018). The future expansion of the aquaculture industry should preferably occur in a resource efficient way (Crab et al, 2012; World Bank, 2013) This includes better use of basic natural resources such as water and land, and fish feed which are the major pre-requisites for aquaculture activities. The addition of organic carbohydrate (CHO) in the biofloc system provides an energy source for microbial organisms to immobilize ammonia or nitrate into microbial biomass (Avnimelech, 1999). This process helps lowering ammonia and nitrite levels, thereby reducing the need for water exchange (Gao et al, 2012; Hu et al, 2014). The application of biofloc systems is beneficial for immunological responses of whiteleg shrimp against infectious agents (Ekasari et al, 2014; Kim et al, 2014; Verma et al, 2016)

Objectives

Methods

Results

Discussion

Conclusion