Effect of supplementing heterotrophic and photoautotrophic biofloc, on the production response, physiological condition and post-harvest quality of the whiteleg shrimp, Litopenaeus vannamei

Abstract

The effect of supplementing biofloc produced under heterotrophic and photoautotrophic conditions, on the production response, physiological condition and postharvest quality of juvenile L. vannamei, intensively farmed under greenhouse conditions was assessed. Heterotrophic bioflocs were produced under a restricted light condition, using an unspecific marine consortium as inoculum and maintaining the C:N ratio around 10-12. The photoautotrophic biofloc were produced under direct light exposition; using Navicula incerta as inoculum and maintaining the C:N ratio around 2-3. No significant differences on the water quality variables were observed among treatments except for TAN which was higher in the control. The production response was affected and a lower survival and higher FCR were recorded with heterotrophic bioflocs. The hemolymph parameters were similar in shrimp between groups, except for cholesterol which increased by more than 4-fold in the control. The postharvest quality of shrimp was qualified as good in general terms, without significant differences between groups, but the mean of the total qualifiers was slightly better in the treatment with photoautotrophic biofloc. The results of the study suggest that supplementation of both types of biofloc has not negative effect on the water quality, on the physiological condition of shrimp and on their postharvest quality. keywords: Heterotrophic biofloc, Autotrophic biofloc, Pacific white shrimp, BFT system, Postharvest quality, Shrimp physiology, Microbial-based systems