The objective of this study was to evaluate the beneficial effect of Saccharomyces cerevisiae (SC) on growth, intestinal morphometric characteristics, blood indices, redox balance, expression of immune-related genes, and their involvement in disease resistance in sea bream (Sparus aurata). Three hundred healthy sea bream fingerlings were allocated into equal four groups (15 fish per hapa). The first group was served as a control and received a basal diet, while the other three groups were fed diets containing 1, 2, and 4 g/kg diet SC, respectively. At the end of week 16, the daily weight gain, specific growth rate, and feed utilization were significantly higher in the SC2 and SC4 groups than the control (p < 0.05). SC dose-dependently improved intestinal morphology, and the 4 g/kg diet significantly increased dry matter, crude fat, and crude protein percentage of body composition when compared with the control group. The 4 g/kg SC boosted innate immune response and phagocytic activity, and all SC-supplemented diets improved total protein, glucose, triglycerides, and urea concentrations, as well as intestinal digestive enzymatic activities. All estimated oxidative markers were significantly enhanced in the group that received 4 g/kg SC when compared with the control and other SC groups (p < 0.05). Feeding the fish a diet supplemented with 4 g/kg SC markedly regulated the expression of HSP70, IGF1, and IL-1β genes. In addition, the 4 g/kg SC-supplemented diet was the most effective in protecting the fish against Vibrio parahaemolyticus challenge. In conclusion, SC-enriched diet improved growth performance, intestinal morphology, redox homeostasis, and immune response of S. aurata with the 4 g/kg concentration as the most effective.

This study investigated the effects of dietary addition of green algae and diatoms on reproductive hormones, redox status, and immunity response, with special emphasis to the influence of these phytobiotics on the expression of interlukine-1β (IL-1β) in Whiteleg Shrimp (Litopenaeus vannamei). The experiment was conducted during the 2022 season, during which the broodstock were fed equal proportions of different components: Spirulina platensis (SP) at 5%, T. weissflogii (TH) at 5% and a mixture of SP and TH in a 2.5:2.5 ratio as well as the control group (basal diet). The levels of follicle stimulating hormone (FSH), luteinizing hormone (LH) and progesterone were significantly higher in the groups fed TH alone or together with SP compared to the control group (p<0.05). The higher concentration of estrogen hormone was observed in TH treated group compared to the control and the other treated groups (p<0.05). With regard to male reproductive hormone, non- significant changes were detected between the control and all examined groups for FSH (p=0.1504) and LH (p=0.4550). Meanwhile the concentration of testosterone improved significantly in the TH group compared to the control or other treated groups (p<0.05). Improved photomicrograph of ovarian lobules, ejaculatory and seminiferous duct through co-treatment with SP and TH supported these findings. The levels of malondialdehyde were notably shrunken in the group that received TH alone or in combination with SP compared to the control group. Conversely, the transcription of interlukine-1 β, catalase activity, and the concentrations of immunoglobulin G and M significantly induced in aforementioned two treated groups compared to the control and SP treated group (p<0.05). The values of glutathione, total antioxidant capacity and superoxide dismutase activity were significantly higher in TH treated group compared to the control (p<0.05). In conclusion, incorporating a blend of SP and TH in a 2.5:2.5 ratio into the diet of Whiteleg Shrimp could serve as an effective strategy to improve the reproductive hormones, immunity status, and redox equilibrium during spawning season .

Evaluating the impact of feeding fermented jojoba meal (FJM) as a plant protein source on growth performance, feed consumption, serum biochemicals, and haematological variables was the goal of the study. Five different levels of plant protein sources (jojoba meal) fermented with Saccharomyces cerevisiae yeast (20%, 40%, 60%, and 80%) were fed to Nile tilapia. One of the five diets, T1, was a control diet without FJM, and the other four diets were designed to include FJM as follows: {T2 (20% FJM), T3 (40% FJM), T4 (60% FJM), and T5 (80% FJM)}. According to the results, the FBW, WG%, DWG, FE, and SGR values of the fish fed diets T1 (control), T2, and T3 were considerably (P<0.05) higher. However, the T5 had the lowest values compared to other group. The survival rate (SR%) of fish fed diets showed high rates of 97.77% in treatments T1 and T3, but there are no significant differences in this regard. Furthermore, there was no significant difference in tilapia fish FI, FCR, PER, or PPV% between groups. The outcomes demonstrated improvements in hematological and blood biochemical indices during therapy as compared to control. As a result, FJM is advised at a level of T2 (20% FJM) and T2 (20% FJM) diet, with no adverse effects on Nile tilapia fish growth performance, feed utilization, or blood health of Nile tilapia fish.

The main objective of this study was to evaluate the possible synergistic effectsof Bacillus subtilis (Bs) and Chlorella vulgaris (Cv) on growth performance, feedutilization, hematological and biochemical variables and immune response of Niletilapia (Oreochromis niloticus) monosex fingerlings. 210 O. niloticus fingerlings(with an average weight of 3.55 g placed in 21 aquarium/triplicates for eachtreatment) were divided into six test diets enriched with Bs (3 or 6 g per kg diet), Cv(2 and 3 g per kg diet) or both Bs and Cv for a period of 14 weeks, in addition to acontrol diet. The data showed that fish fed Bs or/and Cv had higher final bodyweights, weight gains, and specific growth rates than the control group, according tothe data; the fish fed diets containing Bs and Cv had the highest growth rates. Fishfed Bs and/or Cv had lower feed conversion ratios. Moreover, fish fed both Bs andCV had the lowest ratio. The hematological and biochemical variables showedsignificant differences between the groups with normal values. The abovedemonstrates the importance of feeding (O. niloticus) monosex diets rich in B.subtilis and C. vulgaris to improve growth performance and general health.

This experiment was designed to study the main effect of stocking size and stocking densitylevels and their interactions on growth performance, feed utilization, proximate chemicalanalysis of whole-body fish, some biochemical, hematological parameters, and liverfunction, of Nile tilapia (Oreochromis niloticus) fingerlings. All stocked fingerlings inenclosures (hapas) were cultured for 84 days. A (2 × 3) factorial design involved a total of240 fingerlings of two different stocking sizes – beginning weight (5.94±0.70g and20.90±0.91g) that were stocked at three different stocking densities (5, 10 and 15 fish/m3),respectively in twelve enclosures (hapas 1×2×1 m - 2m3) (duplicated for each). At the endof this experiment, the results indicated that final BW, (WG, ADG, SGR, RGR) and feedutilization (FCR and PER) of fish increased with increasing stocking size. The stocking size20.90 gm (W2) released the highest significantly (P0.05).

The present study was carried out in cement ponds with surface area of 4m2 and working volume of 4m3 to investigate the potentiality of using new bio-organic fertilizer (vermicompost) produced though recycling aquaculture solid wastes using earthworm. The efficiency of three types of the vermicompost were tested in the present study. Three species of vermicomposting-earthworm were recruited in the vermicomposting of aquaculture sludge without or with sawdust or sugar-bee. Mono sex Nile tilapia with initial weight 22.88 ± 0.14 g the fish were stocked at the density of 80 fish per pond (4m3). Fish in all treatments were fed (25% protein commercial diet) at a feeding rate of (3% of BW daily), 6 days a week for14weeks. Twelve cement ponds were assigned for four treatments as following: control treatment using cow dung as conventional organic manure (T1); vermicompost of only aquaculture sludge (T2); vermicompost of a mixture of aquaculture sludge and sawdust (T3) and vermicompost of a mixture of aquaculture sludge and sugar beet bagasse (T4). All ponds received 3 g urea and 10 g single super phosphate/pond/fortnights as they were provided with continuous aeration. Compared with the control group (T1), fish fed in ponds T4, T3 and T2, respectively, showed the best values ​​of feed conversion ratio, highest values ​​of final weight, weight gain, specific growth rate and protein efficiency ratio. The same trend was observed in total protein, albumin and globulin. The levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) of fish reared in ponds enriched with T1 were significantly higher. From the above, it is clear that vermicompost made from a mixture of aquaculture wastes was better than cow manure as organic fertilizer in fish ponds, especially when there were water quality improving materials such as sugar beet pulp or sawdust. this study can be concluded that use of vermicompost from the mixture of water sludge with sugar beet pulp had a better effect on performance, survival and chemical composition without changing the biochemical parameters.