Synbiotic containingKappaphycus alvarezii, Spirulinasp.andHalomonas alkaliphilaimproves survival, growth and vibriosis resistance in whiteleg shrimp (Litopenaeus vannamei) post-larval culture

Abstract

The high losses in shrimp production due to mortality caused byVibrioopportunistic pathogens still constitute a significant challenge in the shrimp industry. Synbiotic feed supplementation appears to be a promising control strategy to maintain healthy shrimp stock. In this study, the effects of synbiotic-containing prebiotic seaweedsKappaphycus alvareziiandSpirulinasp. as well as probioticHalomonas alkaliphilawere evaluated on the survival, growth, and vibriosis ofLitopenaeus vannameiduring the post-larval stage. Five different feeds were tested: commercial feed, prebioticsK. alvareziiandSpirulinasp.-supplemented feed, and synbiotic-supplemented feed usingK. alvarezii, Spirulinasp. and probioticH. alkaliphilawith different concentrations of 108, 109, and 1010CFU.kg−1. Following 14 days after the feeding test, the highest shrimp survival (91.46 ± 0.05%) was obtained in the treatment group fed with synbiotic-supplemented feed containing 0.375%K. alvarezii, 0.125%Spirulinasp., andH. alkaliphilaat 109CFU.kg−1(p< 0.05). A 7-day challenge test against opportunistic bacteriaVibrio harveyiiwas then performed using three treatment groups: (1) synbiotic, containing 0.375%K. alvarezii, 0.125%Spirulinasp., andH. alkaliphilaat 109CFU.kg−1; (2) prebiotic, with 0.375%K. alvarezii, 0.125%Spirulinasp.; and (3) control, using commercial feed. The highest shrimp survival of (79.9 ± 0.05%) was found in the synbiotic treatment group, followed by the prebiotic and control treatment groups (p< 0.05). Overall results suggested that synbiotic-supplemented feed containing 0.375%K. alvarezii, 0.125%Spirulinasp., andH. alkaliphilaat 109CFU.kg−1significantly improved shrimp survival even when challenged withV. harveyii. Thus, this synbiotic can be potentially applied as an alternative biocontrol strategy against vibriosis in intensive shrimp post-larval culture.