Effects of Artemia nauplii bioencapsulated with Lactococcus lactis subsp. lactis CF4MRS and sodium alginate on edwardsiellosis protection and digestive enzyme production in climbing perch larvae, Anabas testudineus (Bloch, 1792)

In this study, climbing perch larvae were administrated with different diet treatments: Artemia nauplii enriched with 10⁸ CFU mL⁻¹ L. lactis (LA); nauplii enriched with 0.5 g L⁻¹ sodium alginate (SA); nauplii enriched with 0.5 g L⁻¹ sodium alginate containing 10⁸ CFU mL⁻¹ L. lactis (LSA); and non-enriched nauplii as the control (A). Throughout the 14-day observation period, fish larvae survival rate significantly increased to 50% (P <.05) in the group fed with LSA, followed by LA (41.7%) and SA (31.7%) while only 20% survival rate was observed in the control. The highest lysozyme activity was recorded in LSA (13.89 units mg⁻¹ protein), followed by LA, SA, and A. Fish larvae treated with LA also showed a significant increase in lipase (P =.024) and amylase activities (P=.003) compared to those treated with LSA and SA. Our study indicated that L. lactis and alginate or the combination of both treatments (LSA) could improve the survival rate by upregulating their innate immune response.