BACKGROUND: Vitamins are considered an essential part in diet of aquatic animals. OBJECTIVES: This study was carried out to assay the effect of different levels of vitamin E on growth performance, carcass compositions and blood parameters of common carp fingerlings (Cyprinus carpio). METHODS: Total number of 96 common carp fingerlings weighing 15.49 ± 3.64 g were randomly distributed into 12 fiberglass tanks in four treatments group including control (without added vitamin), 100, 200 and 400 mg/kg vitamin E in three replicates and kept at a density of 8 fish per tank for 10 weeks. RESULTS: Results showed that the highest weight gain, percentage of body weight increase, mean daily growth, specific growth rate, condition factor and the lowest food conversation ratio were observed in fish fed with 200mg/kg vitamin E but no significant differences were seen compared to other treatments (p>0.05). Fish fed with 200mg/kg vitamin E had the highest (p>0.05) contents of protein and ash compared to control group. There was an increase in values of RBC, Hct and Hb in fish fed with 100, 200 and 400 mg/kg vitamin E in comparison with control group. Significant differences were observed in MCHC in fish fed with 100 mg/kg vitamin E compared to control and fish fed with 400 mg/kg, also treatment 200 mg/kg with treatment 400 mg/kg vitamin E (p<0.05). Fish fed vitamin E in 200 and 100 mg/kg had the highest WBC count. Fish fed with different levels of vitamin E had higher lymphocyte in comparison with control group and fish fed with 100 mg/kg had significant difference with control in lymphocyte (p<0.05). CONCLUSIONS: Vitamin E in level of 200 mg/kg can play an important role to enhance growth performance, nutrition efficiency and improving blood indices and support cell immunity in common carp fingerlings.

BACKGROUND: Recently chitosan nanoparticles have been applied as an immunostimulant and adjuvant in biomedical fields. OBJECTIVES: In this study the adjuvant effects of nanochitosan, derived from shrimp shell's chithin, on immunogenicity of Aeromonas hydrophila vaccine in common carp were evaluated. METHODS: Totally 300 juvenile common carp (51±5.6 g, Mean ±SD) were randomly divided into four groups each contained three subgroups with 25 fishes. Groups 1, 2 and 3 were immunized intraperitoneally with A. hydrophila vaccine. No adjuvant used in group 1, but nanochitosan and freund adjuvant were used with vaccine in groups 2 and 3 respectively. Group 4 (Control) injected with normal saline instead of vaccine. Fish were immunised at days zero and 14 and fishes were reared in the same situation for 6 weeks. Serum samples were taken every other weeks and immunological parameters including WBC, serum lysozyme and bactericidal activity, serum complement activity, NBT reduction activity, total protein and globulin levels and anti A.hydrophila antibody titer were compared among the groups. At the end of experiment all groups were challenged with LD50 concentration of A. hydrophila and mortality recorded for ten days. RESULTS: WBC, serum lysozyme and complement activity, NBT activity, globulin level and anti A.hydrophila antibody titer were increased in nanochitosan and freund groups compare to control group (P<0.05). Serum bactericidal activity and serum albumin level showed no significant change among the groups (P>0.05). Challenge mortality decreased in immunised groups compare to control. CONCLUSIONS: Nonochitosan posses proper adjuvant effects which is comparable with freund adjuvant and can be a good candidate as an alternative to current adjuvant in fish vaccines.

BACKGROUND: In recent years, medicinal plants have becomean important option for use in aquaculture industry. Objectives: This study was conducted to determine meanlethal concentration (LC50) and investigated the anesthetic effectof Topped lavender essential oil (Lavandula angustifolia) on common carp(Cyprinus carpio) juveniles. Methods:Mean lethal concentration of essential oil was calculated based on the OECD(Organization Economic Cooperation and Development) standard in static system.For determining  LC50, 150common carp juveniles with mean body weight of 26.96 ± 1.98 g were used in 6groups and one control group and each group with three replications (7juveniles were used for each replication). After Compatibility period (about 2weeks), juveniles were exposed to different concentrations including 71.12,72.11, 73.11, 74.13, 75.16 mg/l that were calculated by logarithmic formula.Juvenile behavioral changes and mortality were recorded in the time period at24, 48, 72 and 96 hours after exposed to Topped lavender essential oil.Determination of Topped lavender essential oil anesthetic effect was done in 6groups (with 3 replicates), as 10 fish exposed to increasing concentrationsincluding 0 (control), 160, 165, 170, 175 and 180 mg/l. Results: Mean lethal concentration(LC50) after 96 hours was obtained 99.70 mg/l. The lowest time for completionof anesthesia (stage 3 anesthesia) was obtained at a concentration of 170 mg/lwith 3.74± 0.35 min and the full recovery of this concentration was obtained at3.91±0.55 min. The results showed that the best anaesthetic concentration ofTopped lavender essential oil was 170 mg/l. Conclusions: It seems that Topped lavender essential oilcould be used as anesthetic agent