This research examined the role of nano curcumin (NC) on growth performances, body composition, and blood parameters of red tilapia (Oreochromis sp.) challenged with Aspergillus flavus. Fish (5.0 g ± 0.30) were randomly distributed in four equal groups (20 fish per pond in triplicates) and fed various concentrations of NC fortified with 0 (Control), 40 mg/kg (NC1), 50 mg/kg (NC2), and 60 mg/kg diet (NC3) of nano curcumin. After eight weeks of the feeding trial, the fish were challenged with A. flavus for 15 days, and the cumulative mortality was recorded. Fish fed with different concentrations of NC improved significantly (p < 0.05) the growth performances, feed utilization, and survival rate. There was no significant (p > 0.05) difference between NC2 and NC3 treatments. However, NC3 exhibited higher performances. Fish feed supplemented with NC decreased the mortality rate when challenged with A. flavus. Hence, dietary supplementation of NC enhanced the growth and health status of Oreochromis sp. and protected it from A. flavus infection. This study suggests the optimum inclusion level of NC is a 50–60 mg/kg diet.

The present study investigated the effect of Chlorella vulgaris on growth performance, feed consumption, body composition, and immune response of white shrimp (Litopenaeus vannamei) against Vibrio parahaemolyticus infection. Shrimps (4.00 ± 0.04 g) were divided into five groups (3 replicates/20 each) in 15 hapa (1 m³) and cultured for 56 days with five C. vulgaris experimented diets at five different concentrations (0, 15, 20, 25, and 30 g/kg feed). Growth performance, feed utilization, biomass, and body composition (protein, lipid, and ash) were analyzed and revealed significant increase (P < 0.05) in shrimp fed the high C. vulgaris diet. Additionally, the survival rate of shrimp in all experimental feeds was improved, but was not significant. Shrimp fed with C. vulgaris at different concentrations showed significantly (P < 0.05) higher antioxidant activity. The study showed that shrimp fed with a concentration of 30 g/kg C. vulgaris in the diet showed significantly (P < 0.05) highest disease resistance against the pathogen tested. Hence, dietary C. vulgaris might be used to improve growth performance, feed utilization, body composition, and immune biomarker responses, leading to disease resistance in cultured shrimp.

The present study tested the symbiotic effects of dietary multi-strain Bacillus probiotics (MSB) (Bacillus licheniformis, B. pumilus, and B. subtilis) in Nile tilapia (Oreochromis niloticus) exposed to Aspergillus flavus infection. Furthermore, this study investigated water quality, growth performance, blood metabolites, histological morphology, immune regulatory genes, and resistance to A. flavus infection. For 70 days, fish (n = 240) were divided into four groups in triplicate: T0 (control group; MSB0), T1 (1 g/kg, MSB1), T2 (2 g/kg, MSB2), and T3 (3 g/kg, MSB3). The immune response was then assessed by challenging all fish groups with the A. flavus pathogen. The results showed that the rearing water quality, fish growth, and blood parameters, as well as total proteins, albumin, globulins, and amylase activity were significantly (P < 0.05) increased in all MSB-treated groups with the best results in MSB2 and MSB3 groups. Meanwhile, the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), cholesterol, and glucose levels were significantly (P < 0.05) modulated, particularly at higher concentrations of the probiotic mixture (MSB3 group). Fish fed with various levels of MSB showed a maintained histological structure of the hepatopancreas, intestine, and spleen tissues. The mRNA expression of growth hormone (GH), insulin-like growth factor-1 (IGF-1), insulin-like growth factor receptor-1 (IGF-1R), and interleukin-8 (IL-8) were increased in a dose-dependent manner due to MSB dietary inclusion (P < 0.05). Conversely, the mRNA expression of interleukin-1β (IL-1β) gene was significantly decreased in MSB groups compared to untreated group (P < 0.05). Surprisingly, supplemented groups in Bacillus spp. probiotics exhibited significant modulations in all computed parameters. MSB supplementation improved the pathogenic tolerance of tilapia after change with A. flavus. The integration of growth performance, biochemical, and transcriptomic results confirms that the dietary intervention of multi-strain Bacillus spp. is symbiotic and enhances the benefits for the maintenance of O. niloticus’ health, growth, and digestion. This is achieved by supporting growth genes, reducing inflammatory genes, and enhancing immune-antioxidant resistance to combat A. flavus infection.

Probiotics are becoming increasingly popular as eco-friendly alternatives in aquaculture. However, there is limited research on their impacts on the reproductive efficiency of Red Tilapia (Oreochromis niloticus x O. mossambicus) broodstock. Therefore, this experiment aimed to explore the combined effects of selective probiotics Bacillus subtilis and B. licheniformis (BSL; 1:1) added to water on blood hematology, serum metabolites, gonadal histology, reproductive performance, and reproductive associated genes in Red Tilapia broodstock. Tilapia broodfish weighing 140–160 g were stocked in four treatment groups: control (T0), and the other three groups were added different levels of BSL to the water as follows: T1 (0.01 g/m³), T2 (0.02 g/m³), and T3 (0.03 g/m³), respectively. Results indicate that BSL administration significantly improved RBCs, hemoglobin, hematocrit, MCH, and MCHC, with the highest improvement seen in the T3 group (P < 0.05). BSL added to the fish water significantly enhanced serum protein fractions (total protein, albumin, and globulins), while AST, ALT, ALP, creatinine, uric acid, and glucose were significantly diminished in a dose-dependent way (P < 0.05). Adding 0.02–0.03 g/ m³ of BSL resulted in higher antioxidant status (superoxide dismutase and catalase) compared to other groups (P < 0.05). Testosterone levels were higher in T3 than in other groups (P < 0.05). All female hormones (LH, FSH, estradiol, and progesterone) were substantially augmented by the addition of BSL. Additionally, the BSL groups exhibited higher GSI, HSI, VSI (male only), egg diameter (mm), mean number of fry/fish, and mean fry weight (g) compared to the control group (P < 0.05). Expression of reproductive-associated genes (vasa, nanos1a, nanos2, dnd1, pum1, AMH, and vtg) were significantly up-regulated in the gonads of fish in the 0.03 g/m³ treatment. The histological gonadal structure exhibited that BSL improved gonad maturation in both genders of Tilapia fish. Overall, adding a mixture of B. subtilis and B. licheniformis (0.03 g/m³ water) can accelerate reproductive performance in Red Tilapia through up-regulation of reproductive genes and enhance the health profile.