Effect of Dietary Administration of Green Macroalgae (Ulva intestinalis) on Mucosal and Systemic Immune Parameters, Antioxidant Defence, and Related Gene Expression in Zebrafish (Danio rerio).

This study investigated the effects of adding green macroalgae gutweed (Ulva intestinalis) powder to zebrafish (Danio rerio) feed at different levels on innate immune responses, antioxidant defence, and gene expression. A total of 600 zebrafish (0.3 ± 0.08 g) were randomly allocated to 12 aquariums in four treatments with three replicates (50 fish per aquarium). Zebrafish were fed with different levels of U. intestinalis powder 0, 0.25, 0.5, and 1% for eight weeks. Whole-body extract (WBE) immune parameters including total protein level, globulin level, and lysozyme activity were evaluated and revealed statistically significant increased in all U. intestinalis supplemented groups compared to the control (P < 0.05). However, mucus immune parameters (total protein, globulin, and lysozyme) were statistically different in only 1% gutweed supplemented groups from other groups. While glutathione peroxidase (GPx) and superoxide dismutase (SOD) increased with the addition of gutweed (P < 0.05), catalase (CAT) did not change (P > 0.05). The study results showed that dietary gutweed remarkably upregulated immune-related genes such as lysozyme (Lyz) and Interleukin 1 beta (IL-1ß). Antioxidant-related genes (SOD and CAT) and growth-related genes, including growth hormone (GH) and insulin-like growth factor-I (IGF-1), were remarkably upregulated with gutweed treatment (P < 0.05). In conclusion, dietary U. intestinalis showed beneficial effects on immunity, and same effects were observed in case of antioxidant and growth related genes expression in zebrafish.

Combined or Individual Effects of Dietary Probiotic, Pediococcus acidilactici and Nucleotide on Reproductive Performance in Goldfish (Carassius auratus).

This work evaluated the effect of dietary supplementation of probiotic, Pediococcus acidilactici and nucleotide (combined or individual) on reproductive performance including semen quality (motility and density) and egg indices (egg diameter, ovum diameter, absolute fecundity, relative fecundity, gonadosomatic index, hepatosomatic index, fertilization rate, and hatching rate) in goldfish (Carassius auratus). Fish (46.9 ± 2.15 g) were acclimatized and divided into eight experimental diets supplemented with P. acidilactici different concentrations (0.1, 0.2, and 0.3% diet) and nucleotides (0 and 0.5% diet) for 180 days. Female fish fed experimental diets showed significant differences in reproductive parameters as compared to control diet (P < 0.05). Combined diet (probiotic 0.2% and nucleotide) had the highest percentage and duration of sperm motility, absolute fecundity, and fertilization success as compared to other diets (P < 0.05). The significance of the results obtained herein underlines the importance of diet in the reproductive processes, supporting the hypothesis that feed additives could improve gamete quality.

Combined or Individual Effects of Dietary Probiotic Pedicoccus acidilactici and Nucleotide on Growth Performance, Intestinal Microbiota, Hemato-biochemical Parameters, and Innate Immune Response in Goldfish (Carassius auratus).

This study investigated the effect of dietary supplementation of probiotic Pedicoccus acidilactici and nucleotide (separately or combined) on growth performance, intestinal microbiota, hemato-immunological parameters, and immunity response in goldfish (Carassius auratus). Fish (average weight 5-6 g) were acclimatized and divided into eight experimental diets supplemented with P. acidilactici of different concentrations (0.1, 0.2, and 0.3% diet) and nucleotides (0 and 0.5% diet) for 6 months. Fish fed with experimental diets showed significant differences in terms of final weight, weight gain, feed conversion ratio, daily growth rate, and condition factor when compared to control diet (P < 0.05). Fish fed with probiotic (0.3%) separately and combined with nucleotide (0.5%) had highest RBC and WBC when compared to other diets (P < 0.05), while the highest values for Hb and Hct as well as total protein, glucose, albumin, and globulin were observed in probiotic (0.2%) and nucleotide (0.5%) combined diet. Serum lysozyme and anti-protease activities were significantly higher in probiotic (0.1 and 0.2%) and nucleotide (0.5%) combined diets. Similarly, these two diets combined showed the highest colonization of P. acidilactici when compared to other diets. In conclusion, combined dietary probiotic and nucleotide improve the growth performance, hemato-biochemical parameters, and intestine growth in C. auratus.

Effect of a Probiotic Containing Bacillus licheniformis and Bacillus subtilis and Ferroin Solution on Growth Performance, Body Composition and Haematological Parameters in Kutum (Rutilus frisii kutum) Fry.

This study aimed to assess the efficacy of BioPlus 2B, a probiotic containing Bacillus licheniformis and B. subtilis and Ferroin solution on growth performance, body composition and haematological parameters in kutum, Rutilus frisii kutum, fry. The fish were fed dry pellets containing various ratios of probiotics and Ferroin for 60 days after absorption of the yolk sac. At the end of the trial, growth indices (final weight, weight gain, specific growth rate, daily growth rate, food conversion ratio and condition factor), body composition (crude protein, crude lipid, ash and moisture) and haematological parameters [haematocrit (Hct), haemoglobin (Hb), red blood cells (RBC), white blood cells (WBC), neutrophils (NEUTR), lymphocytes (LYM), mean cell volume (MCV), mean cell haemoglobin (MCH) and mean cell haemoglobin concentration (MCHC)] were assessed. Regarding body composition, total protein levels were higher, and ash, moisture and lipid levels were lower in fish receiving the probiotic and Ferroin treatments compared with the control group (P < 0.05). Fish receiving diets supplemented with probiotics and Ferroin solution showed significantly better growth than those fed the basal diet (control). RBC, Hct, Hb, MCV, MCH and LYM were all highest in fish fed probiotic (1.6 × 10(9) CFU/g dry pellet) + Ferroin solution (7 mg/kg dry pellet) + dry pellets. These results indicate that the combination of probiotic and Ferroin solution represents an effective dietary supplement for improving carcass quality, growth performance and haematological parameters in kutum fry.

Physiological characteristics and stress resistance of great sturgeon (Huso huso) juveniles fed with vitamins C, E, and HUFA-enriched Artemia urmiana nauplii.

This study was carried out to examine the effect of Artemia urmiana nauplii enriched with HUFA, and vitamins C and E on stress tolerance, hematocrit, and biochemical parameters of great sturgeon, Huso huso juveniles. Cod liver oil (EPA 18% and DHA 12%), ascorbyl-6-palmitate and alpha-tocopherol acetate were used as lipid, and vitamin C and E sources, respectively. Beluga juveniles at the stage of first feeding (69.7 +/- 5.9 mg body weight) were randomly divided into five treatments and three tanks were assigned to each diet. All fish groups were fed non-enriched Artemia for the initial 5 days and then fed enriched Artemia for 7 days. Juveniles were fed with Artemia enriched with HUFA + 20% vitamin C (C group); HUFA + 20% vitamin E-enriched Artemia nauplii (E group); HUFA + 20% vitamin C + 20% vitamin E (C and E group); HUFA without vitamins (HUFA) and non-enriched Artemia (control). After the period of enrichment, Juveniles were fed with Daphnia sp. from the 13th to the 40th day. At day 40, the fish were transferred directly from fresh water (0.5 ppt) to brackish water (6 ppt for 4 days and 12 ppt for 2 days) and warm water (from 27 to 33 degrees C) to evaluate juvenile resistance to salinity and thermal shocks. Moreover, all treatments were separately exposed to freshwater in tanks with the same capacity as used for osmotic and thermal tests (as fresh water control). The addition of vitamins C, E, and C + E to HUFA significantly increased fish resistance to 12 ppt salinity and temperature stress tests, whereas survival was not significantly different among challenges at 6 ppt. There was no significant difference in the hematocrit index under stress conditions. Enrichment had significant influence on plasma Na(+) level in the C group on the 4th day at 6 ppt. Na(+) and Ca(2+) concentrations in C, E, and C and E groups on the 1st day at 12 ppt, and Ca(2+) level in E group on the 2nd day at 12 ppt were lower than the other groups. The glucose level in the C and C and E groups was lower than the other treatments on the 1st day at 12 ppt and the 2nd day at 33 degrees C. Regardless of Artemia enrichment, plasma ions (Na(+), K(+), Ca(2+), and Mg(2+)) and glucose concentrations in fish exposed to salinity stress tests were higher than fish in fresh water. Glucose concentration in plasma also increased after 2 days at 33 degrees C. Although most of our results were not significantly different, the use of vitamins C, E, and HUFA in Artemia enrichment can improve Juveniles tolerance under stress conditions, and regardless of enrichment, these data show that beluga juveniles are partly sensitive to high salinity and temperature.