IRANIAN JOURNAL OF AQUATIC ANIMAL HEALTH
Year:2018 | Volume:4 | Issue:1 |Papers Count:10

Many works have emphasized that natural healthy agents have payed attentions nowadays as the mostly used synthetic therapeutics might have some undesirable actions. One can think that some natural nutrients would be better and safer than synthetic ones. Some of these matters, such as natural agents, often show antioxidant effects. These components into natural agents may be helpful to health the of consumers and also to the stabilization of nutrients.

The antibacterial effects of methanol, ethanol, chloroform extracts and alcalase hydrolysis of Cerastoderma and Didacta were investigated against Salmonella typhi, Salmonella paratyphi and Staphylococcus aureus by disk diffusion method, Minimum Inhibitory Concentration and Minimum Bactericidal Concentration. Methanolic and ethanolic extracts of Cerastoderma showed the highest effects against S. typhi (20. 33 ± 0. 33 and 12. 33 ± 0. 33) and S. paratyphi (22. 66 ± 1. 45 and 15. 33 ± 0. 33), however, the same effects against S. aureus (18. 00 ± 0. 00 and 17. 00 ± 0. 00) were observed for two bivalves. Chloroform extract of Cerastoderma and Didacta showed similar effects in controlling S. paratyphi (8. 00 ± 0. 58 vs 10. 00 ± 0. 57) and S. aureus (16. 00 ± 1. 15 vs 16. 00 ± 1. 15) in concentrations of 10 and 5 mg ml-1. Chloroform extract of Cerastoderma exhibited higher effect than that from Didacta against S. typhi (11. 00 ± 1. 73 vs 8. 00 ± 0. 58) and the dilution of 10 mg ml-1 had the most suitable performance. The enzymatic hydrolysis of the Cerastoderma and Didacta showed the same performance in controlling of S. typhi (13. 67 ± 4. 37 vs 13. 33 ± 1. 76) and S. paratyphi (17. 00 ± 0. 58 vs 15. 33 ± 1. 45). However, the enzymatic hydrolysis of Cerastoderma showed better effect than that of Didacta in controlling S. aureus (18. 00 ± 1. 15 vs 13. 00 ± 2. 30), and the 10 and 5 mg ml-1 dilutions were the most appropriate concentrations. It is concluded that Cerastoderma can be used as a resource with potent antibacterial compounds in the preparation of natural antimicrobial agents.

Our study was concentrated on the effect of garlic peel on haematological parameters, biochemistry and digestive enzymes on beluga juvenile (Huso huso) with mean body weight of 18. 41 ± 0. 89 g after the feeding trial for 90 days. Garlic peel powder added with 0%, %0. 5, %1, %1. 5 and %2 of feed to basic sturgeon diet (49% protein and 14% lipid). ultimately, haematological parameters, biochemistry, digestive enzyme activity were evaluated. Results showed that the hemoglobin (Hb) was remarkably greater in the treatment fed garlic peel diet in comparison with the control (p<0. 05), while others blood indices did not significant differences (p>0. 05) between juveniles fed control and garlic peel supplementation diets. The group fed 1. 5% garlic peel showed highly significant different in total protein (p<0. 05). However, Glucose, triglyceride, total lipid, cholesterol, ALP and ALT were significantly decrease in the juvenile fish fed by the 1. 5% garlic peel diet compare to the control (p<0. 05). The fish treated with 1. 5% garlic peel exhibited significantly increase in amylase, protease and lipase compare to the control (p<0. 05), but trypsin, chymotrypsin and pepsin were not affected (p>0. 05). These results indicated that garlic peel powder in 1. 5% level, improved blood indices and digestive enzymes activity of beluga sturgeon.

This research was carried out to survey the ffects of dietary of Lentinula edodes mushroom extract as a feed supplement on growth performance and survival rate, immune response, hematological and biochemical characteristics of beluga juvenile (Huso huso). Four hundred and fifty fish after acclimation with average weight of 40. 45 ± 5. 72 g were fed in a wholly randomized design in 5 treatments (basic diet containing 0% (control), 00. 5%, 1%, 1. 5% and 2% L. edodes mushroom extract) and 3 replicates. During the experiment (56 days), a total of eight samples were taken in 8 weeks. The mean of data were analyzed using oneway ANOVA and Duncan's post hoc test at 5% level. Results indicated that administration of 2% of mushroom extract for 8 weeks improved weight gain, specific growth rate and feed conversion ratio of beluga (P<0. 05). Among the investigated hematological indices, Supplementing 2% L. edodes resulted in increased levels of the erythrocytes (RBC), hemoglobin (Hb), haematocrit (Hct) in comparison with the control group (P<0. 05). At the end of the assay, there were significant decreased in some of the biochemical parameters (Cholesterol, alkaline phosphatase (ALP) and alanine aminotransferase (ALT)) in the treatments containing mashroom extract (P <0. 05). Also the activity of serum lysozyme activity and superoxide dismutase (SOD) Among immune parameters studied were increased in group of 2% of L. edodes compared to other treatments (P <0. 05). These results indicated that the addition of supplemental mashroom extracts, especially at 2% level to the beluga juveniles diet, were improved the growth performance, some hematological and biochemical parameters and immune response of beluga juvenile.

Study of gut tissue structure in fish is important as the fish culture increases and then, more information is required regarding to feeding and nourishment. Then, the present study aimed to describe the histological and histochemical characteristics of GALT in the pike, Esox lucius, from the Anzali wetland. In this regards, 20 E. lucius were collected from the Anzali wetland. Tissue samples from different parts of gut were fixed in Bouin’ s solution. Tissue slides were prepared using tissue preparation techniques and stained with hematoxylin and eosin (H&E), Periodic acid– Schiff (PAS), Alcian blue and AB-PAS. In E. lucius the internal surface of gut was folded and coated by simple columnar cells and goblet cells. Goblet cells positively reacted to PAS, AB and ABPAS, due to mix acidic and neutral glycoproteins containing. Eosinophilic granular cells were detected in lamina propria. GALT represented throughout the gut mucosa in the epithelium and lamina propria. Lymphocytes increased in number toward the posterior part of intestine (p<0. 05).

The present research was aimed to assess the effect methanol extract from Ulva rigida on biochemical response and digestive enzyme activities in Mugil cephalus. A control diet without and three other experimental diets were supplemented by U. rigida extract (UE diet) at the inclusion levels of 5, 10 and 15 g kg-1 diet, respectively. One hundred and twenty grey mullets with the mean weight of 14. 95 ± 2. 01 g were randomized into 12 tanks and fed twice per day (09: 00 and 17: 00) for 60 days. After 60 days of the feeding trial, serum total protein and globulin levels of the fish receiving UE diet had incremental trend and better performance, except for samples fed UE5. The UE10 diet resulted in the highest amylase, lipase and protease activities. Significantly different was observed in survival rate, glucose and triglyceride levels between control and UE supplemented groups (p< 0. 05). There was significant reduction in glucose and triglyceride levels in the fish received UE diet compared to the control (p<0. 05). According to the present results, U. rigida extract as a new introduced dietary supplement is suitable for improving metabolism of carbohydrate and enhancing digestive enzyme activities in grey mullet.

Since infectious pancreatic necrosis virus (IPNV) is the most predominant strain causing fatal viral disease in Iranian fish farms, an inactivated vaccine for this fatal pathogen was developed. Additionally, the effect of the above-mentioned vaccine was investigated against IPNV using Montanide 1312 VG adjuvant. Two hundred and forty healthy fish with an average weight of 3. 00 ± 0. 45 g were vaccinated using immersion method with ethylene amine-inactivated IPN vaccine in combination with Montanide IMS 1312 VG for 5 min at 11 ± 1° C. The control group was vaccinated with sterile phosphate-buffered saline. The immersed vaccine with Montanide IMS 1312 VG adjuvant increased the expression of immune system genes such as IgM, MX, and CD8 within 30 days of vaccination period. The expression of IgM, Mx (P<0. 05) and CD8 (P>0. 05) genes was higher for the vaccine containing 10g of Montanide than that of 50g of Montanide. In fish vaccinated with the adjuvant, the relative percent survival was notably higher than of fish vaccinated without the adjuvant and the control group. Results showed that the ethylene amine-inactivated IPNV vaccine by the immersion method with Montanide IMS 1312 VG significantly has a strong protective immunity against IPNV in rainbow trout.

In order to study the effect of prebiotic Mito on compensatory growth following one week starvation in common carp, the fish (4. 5 ± 0. 05 g) were examined for 60 days in three treatments. A control fed with non-prebiotic diet with no starvation (T1), a 2nd group starved for one week then fed 0. 2% of prebiotic (T2) and 3rd group received no prebiotic diet after one week starvation. The highest percent of weight gain and specific growth rate and condition factor were obtained in the control followed by T2 with significant differences (P<0. 05). The lowest amount of food conversion ratio and the highest amount of protein efficiency ratio were recorded in T1, too. The mortality rate was zero in all treatments. The number of red blood cells showed insignificant differences between the control and the other groups (P> 0. 05). Hemoglobin and hematocrit values significantly differed between T1 and two other treatments. T2 contained the highest number of white blood cells and lymphocyte while the percent of basophil, eosinophil and monocyte did not differ between treatments significantly (P> 0. 05). So, although the use of 0. 2% prebiotic largely caused compensatory growth in carp but was not so sufficient that exceed those of the control group. However, the addition of prebiotic Mito significantly elevated hematological status of the fish.

Aflatoxins are toxic chemicals that are produced by Aspergillus flavus and Aspergillus parasiticus species of fungi. Aflatoxicosis caused by consumption of aflatoxincontaminated feeds represents one of the serious diseases in most fish species. Due to the lack of information regarding the effects of aflatoxin B1 (AFB1) on farmed Acipenser stellatus, providing practical information for rearing of A. stellatus is imperative. A. stellatus fingerlings with the mean initial weight of 7. 90 ± 0. 12 g were kept in 50 Liter tanks with 10 fish per tank in a one way through water system with well water. Fish were adapted to the rearing conditions. The experimental diets were formulated to contain 1500, 1850, 2300, 2850 and 3500 ppb AFB1 kg-1 diet. Two control diets were also considered. Fish were fed each of the experimental diets in triplicate groups three times a day for 52 days. At the end of the experimental period, there were significant effects (p<0. 05) on WG%, final biomass, condition factor (CF), specific growth rate (SGR) and survival rates with the increase in aflatoxin levels in diets. There were significant differences (p<0. 05) in blood parameters including WBC, RBC, HB and PCV % and also liver enzymes such as AST, ALT and ALP with the increase in aflatoxin levels in diets. 50% of fingerlings perished after 52 days of feeding at the concentration of 3500 ppb AFB1 kg-1. The results of this study revealed that Acipenser stellatus was relatively resistant to aflatoxin B1.

Applying anaesthetic agent is recommended in aquaculture during fish handling specially tagging. However, it should be noted that anesthesia itself is likely to induce stressful condition due to its improper and high concentration. By means of nanoemulsions, drug delivery improves which in turn contributes to fewer amounts of pharmaceutical agents’ usage. In this research, nanoemulsions of clove oil (NCL) and lemonbeebrush (NLB) were used to develop the anesthetic efficacy and reduce the concentration needed for anesthesia in Huso huso (mean weight: 1115 ± 242. 25 g) as an endangered species. Based on the results, anesthesia induction time (s) of stage 3 & 4 was significantly decreased in NCL and NLB when compared to MS-222 (p<0. 05). NCL treated beluga were induced stage 5 anesthesia much quicker than NLB and MS-222. In contrary, recovery time did not show significant difference among treatments (p>0. 05). Among measured biochemical factors, lactate had the highest value in NCL group during anesthesia (p<0. 05). In contrast, lactate level had highest level in NLB, 24h post anesthesia (p<0. 05). NLB and NCL produced higher non-specific immune (Lysozyme and ACH50) enhancements at 0 and 24h post anesthesia. Furthermore, results showed that MS-222 induced increased serum cortisol levels (p<0. 05). Cortisol and glucose were not depressed by NLB and NCL, suggesting that these anesthetics are safer anesthetic for Huso huso as it does not cause immune depression in anesthetized fish.