Hien Van Doan

The current research evaluated the effect of probiotics Lactobacillus casei and resveratrol individually or in combination on growth performance, antioxidant capacity, growth-related genes, and resistance against Aeromonas hydrophila in grass carp ( Ctenopharyngodon idella ). Fish weighing 4.89±0.08 g were divided into four treatments with three replicates and fed with T0: control-without additives; T1: containing Lactobacillus casei ; T2: containing resveratrol; T3: containing a combination of both, all for a duration of 56 days. After the feeding experiment, fish were challenged to the bacterial pathogen A. hydrophila for 14 days. The results showed that the probiotic L. casei and resveratrol, individually or in combination, significantly increased growth parameters compared to the control group (PL. casei and resveratrol individually or in combination (PL. casei and resveratrol, individually or in combination, in increasing growth performance, feed utilization, antioxidant enzyme activity, and the expression of growth-related genes.

Oyster pompano ( Trachinotus anak ) is a commercially valuable marine species widely farmed in Southeast Asia, yet growth heterogeneity remains a persistent challenge in cage aquaculture. To investigate whether body weight influences the intestinal microbiota of this species, we compared the gut microbial communities of small and large T. anak using high‐throughput 16S rRNA gene sequencing. The intestinal microbiota was dominated by Pseudomonadota ( Proteobacteria ) and Mycoplasmatota , together accounting for nearly 80% of total sequences, with additional contributions from minor phyla such as Spirochaetota , Thermodesulfo bacteriota , and Bacteroidota . While alpha‐ and beta‐diversity analyses revealed no significant differences between groups, community composition and structure varied. Smaller fish harbored a more heterogeneous assemblage at the class level and a broader suite of core taxa, including Acinetobacter , Aeromonas , Bdellovibrio , and Comamonas . In contrast, larger fish were dominated by fewer classes, with Photobacterium and Brevinema emerging as distinctive core members. LEfSe analysis identified discriminant taxa between groups, although these trends were not statistically significant after multiple‐testing correction. Network analysis highlighted striking differences in microbial interactions: smaller fish exhibited highly modular, densely connected networks with potential keystone taxa such as Paracidovorax and Ensifer , whereas larger fish displayed simpler, less structured networks indicative of reduced ecological stability. Together, these findings demonstrate that body weight is associated with subtle but ecologically meaningful shifts in microbiota composition, core membership, and interaction networks in cage‐cultured T. anak . This work underscores the potential of microbiome‐informed management strategies to mitigate growth variability and enhance the sustainability of marine aquaculture.

The valorization of agricultural by-products as functional feed additives represents a promising strategy for sustainable aquaculture. This study evaluated the effects of dietary fermented longan peel (FLP), produced through enzymatic hydrolysis and Lactiplantibacillus plantarum fermentation, on growth performance, digestive physiology, gut morphology, innate immunity, and gene expression in Nile tilapia (Oreochromis niloticus) cultured under a biofloc system. Five experimental diets were formulated with graded FLP levels (0, 5, 10, 20, and 40 g kg⁻¹) and fed to fish for eight weeks. Growth indices, including final weight, weight gain, and specific growth rate, improved significantly in fish receiving 20 g kg⁻¹ FLP, following a strong quadratic response pattern. In vitro digestibility assays showed enhanced carbohydrate and protein digestibility, coinciding with increased intestinal amylase and protease activities. Histological analysis indicated that moderate FLP inclusion (10–20 g kg⁻¹) promoted villus height, crypt depth, and epithelial organization. Innate immune parameters, including lysozyme, peroxidase, and alternative complement activity, were markedly elevated in serum and mucus, particularly at 20–40 g kg⁻¹ after eight weeks. Gene expression profiling revealed significant up-regulation of growth-related (IGF-1, GH, NPY-α, Galanin), immune-related (TLR-7, TNF-α, NFκB), and antioxidant-related (hsp70, Keap-1, nrf-2, GST-α) genes in fish fed higher FLP levels, with responses plateauing beyond 20 g kg⁻¹. Overall, FLP supplementation at 20 g kg⁻¹ optimally enhanced growth, digestive efficiency, intestinal health, and innate immune status. These findings demonstrate the potential of fermented longan peel as a cost-effective, bioactive, and sustainable functional feed ingredient for tilapia and other warm-water aquaculture species.

The valorization of agricultural by-products as functional feed additives represents a promising strategy for sustainable aquaculture. This study evaluated the effects of dietary fermented longan peel (FLP), produced through enzymatic hydrolysis and Lactiplantibacillus plantarum fermentation, on growth performance, digestive physiology, gut morphology, innate immunity, and gene expression in Nile tilapia (Oreochromis niloticus) cultured under a biofloc system. Five experimental diets were formulated with graded FLP levels (0, 5, 10, 20, and 40 g kg-1) and fed to fish for eight weeks. Growth indices, including final weight, weight gain, and specific growth rate, improved significantly in fish receiving 20 g kg-1 FLP, following a strong quadratic response pattern. In vitro di-gestibility assays showed enhanced carbohydrate and protein digestibility, coinciding with increased intestinal amylase and protease activities. Histological analysis indicated that moderate FLP inclusion (10–20 g kg-1) promoted villus height, crypt depth, and epithelial organization. Innate immune parameters, including lysozyme, peroxidase, and alternative complement activity, were markedly elevated in serum and mucus, partic-ularly at 20–40 g kg-1 after eight weeks. Gene expression profiling revealed significant up-regulation of growth-related (IGF-1, GH, NPY-α, Galanin), immune-related (TLR-7, TNF-α, NFκB), and antioxidant-related (hsp70, Keap-1, nrf-2, GST-α) genes in fish fed higher FLP levels, with responses plateauing beyond 20 g kg-1. Overall, FLP supple-mentation at 20 g kg-1 optimally enhanced growth, digestive efficiency, intestinal health, and innate immune status. These findings demonstrate the potential of fermented longan peel as a cost-effective, bioactive, and sustainable functional feed ingredient for tilapia and other warm-water aquaculture species.