Journal of Aquaculture Development
Year:2021 | Volume:15 | Issue:2|Papers Count:10

Rainbow trout is one of the most important cultured species in Iran. Despite the progressively increased production of this species during the last decade, there have been many egg quality problems in the hatcheries yet. Thus, in this research we investigated the effects of adding Artemia powder to broodstock diet on Rainbow trout egg quality. Fishes were fed commercial diet for four months, then experimental diets containing 0% (control), 2. 56% (5% replacement), 5. 12% (10% replacement), 10. 24% (20% replacement), and 15. 37% (30% replacement) Artemia powder. Results indicated that the values of absolute and relative fecundity in the treatment 5% were significantly higher than in the rest of treatments and in the control group (p<0. 05). There were no significant differences amongst the treatments and control group in terms of egg number per gram, egg diameter, total protein and total lipid values (p>0. 05). The parentage of the eyed eggs and hatching rates in the experimental treatments were significantly higher than the control group. The values of HUFA n-3 in the experimental treatments were significantly higher than the control group (p<0. 05). in conclusion, based on the results, adding 5% Artemia powder to rainbow trout broodstock diet can improve egg quality of this species.

The effect of different concentrations of dietary Enterococcus faecium on some immune parameters in common carp was carried out on 2019 in Ahmadabad farm. For this purpose, 600 fry with average weight 11. 0 ± 0. 5 g were reared in 12 plastic tanks (50 fish per tank) for 56 days and had been fed by 4 different concentration of E. faecium including [0 (control), 1×107 CFU/g (T1), 1×108 CFU/g (T2), and 1×109 CFU/g (T3)]. The results showed that the most amount of serum lysozyme (46. 2± 2. 7 IU/ml), immunoglobulin M (IgM) (38 ± 0. 9 mg/dl) and components complement system C3 (24. 8 ± 0. 6 mg/dl) and C4 (10. 4 ± 0. 4 mg/dl) obtained in T3 (P < 0. 05). Among the experimental treatments, the highest lysozyme activity and mucus protease activity were measured in T3 (P < 0. 05). However, there was no significant difference among the experimental treatments in alkaline phosphatase activity of the skin mucus samples (P > 0. 05). Based on the obtained results, it seems that applying of E. faecium at the concentration of 1×109 CFU /g in common carp diet can provide positive effects on some serum and skin mucus immune responses.

This study was designed to determine the effects of parameters: temperature, pH and dKH on growth indices of Angelfish (Pterophyllum scalare). For this purpose, in each aquarium, there was specific combinations of temperature, pH and dKH, using design of experiment with Design Expert 7. 0, and in total 14 combinations or treatments, each with 3 repetitions and thus, 3 fishes were entered in each aquarium randomly. In 2 timespans, 1-25 days and 25-40 days, the measurement of body weight and body length was done, and growth indices including: weight gain (WG), length gain (LG) and feed conversion ratio (FCR) were identified. Studying of growth pattern showed that the best mathematical model to show the changes of growth indices was quadratic equation. The interactions between pH × dKH, pH and dKH, had more effects on weight changes. The optimum dKH for weight gain of Angelfish was 7, temperature: 26. 33 and pH: 7. 5. About the factor, FCR, dKH and the interactions between pH × dKH, and temperature × dKH, had the most effects. The optimum temperature to have the least FCR, at the first time period was 26, dKH: 8. 7 and pH: 7. At the second time period, the optimum temperature was 27. 6, pH was 7. 5 and dKH was 7. Besides, none of linear, quadratic and cubic equation, represents the length growth of Angelfish.

This study was carried out to compare the effects of different sources of selenium on growth, survival, and some immunological and hematological parameters of whole female Triploid of rainbow trout (Onchorhynchus mykiss). 10 diets including selenium (selenium sodium), selenium (selenomethionine) and nano-selenium with zero (control), 0. 1 (treatment 1), 0. 5 (treatment 2) and 1 (treatment 3) mg / kg The diet was made. After 8 weeks of nutrition, The final weight was 0. 5 mg / kg Nanoselenium had the highest amount. The highest specific growth factor (4. 26 ± 0. 24) percentage/day was observed in fish fed 0. 5 mg / kg Nanoselenium. The lowest feed conversion ratio (0. 71 ± 023) and the highest weight gain (41. 99 ± 1. 36) g were observed in this treatment, which was significantly different with the control group (P <0. 05). Feeding treatments with nano-selenium also produced the best feed conversion ratio (P <0. 05). Nanoselenium and selenium treatments had significant differences in red and white blood cells, hemoglobin and lysozyme with control (P <0. 05); However, this difference was not observed in treatments fed with selenium (p <0. 05). There was no significant difference in hematocrit in all treatments with the control group (p <0. 05). Immunoglobulin level was significantly different in all treatments on all three sources of nutrition with the control (P <0. 05) and the highest concentration was observed in the one concentration of nanoselenium. The results showed that the addition of nanoseleniums up to 0. 5 mg / kg of food resulted in a good proportion of growth indices, survival, and some blood and immune factors in the fry of the whole female mono-sex Triploid rainbow trout.

In this research the effect of Camellia sinensis on Ctenopharyngodon idella hematological factors was studied. For this purpose 240 juvenile of Ctenopharyngodon idella was selected that initially had average weight of 18. 24+2. 07 gr and after being adapted with environment, were stored in 12 tanks selectively (20 fish in each tank). The camellia siensis was added to the diet in three levels 1. 5% (treatment 2) 3 % (treatment 3) and 5 % (treatment 4) and the diet without camellia siensis was used for control group (treatment 1). Each treatment was repeated 3 times. The fish was fed 3% of their weight. At the end of the 60 day period, 15 fish was randomly selected from each treatment and their blood sample was taken from the caudal vein. The result was showed that amount of RBC and WBC had significant difference in treatment 2 with other treatments (P<0. 05). The Maximum amount in treatment 2 (1. 5%) was 4. 4± 0. 57 (microliter×103) and 6. 74± 0. 74 (gr/dL), respectively. The most improved Biochemical factors were seen in treatment 0. 5 %. Increasing the number of white blood cells and hemoglobin in the treatment of 1. 5% and in the average concentration of globules showed an increasing trend in the treatments of green tea and also a significant increase in serum biochemical factors including albumin and glucose at the level of 1. 5%.

Betanodavirus is known as a serious threat to fish health and causes economic damages to the mariculture industry and aquaculture. Given the importance and worldwide prevalence of viral nervous necrosis disease, this review provides new information on the characteristics of Betanodavirus, its modes of transmission, diagnosis, and ways to its control and prevention. Recent studies have suggested the possibility of the presence of Betanodavirus in the Iranian southern waters and the transmission of its infection in wild and farmed fish in different parts of the Persian Gulf and due to the location of the Persian Gulf and its relation to the high seas and transmission of the virus through water and carriers, it is possible to spread the infection in sensitive fish. On the other hand, the small size of the virus, the high rate of mutation enables contamination of new hosts and its high resistance and survival in aquatic ecosystems poses a serious threat to the contamination and loss of marine and cultured fish in the region. Therefore, to prevent the destruction of sensitive fish stocks in the region, comprehensive study of the disease, screening of different species of fish susceptible to viruses and accurate and rapid identification of Betanodavirus, the use of effective vaccines in the field of fish farming in the cage culture, it seems an urgent and inevitable necessity in the country.

Obstacles and problems of shrimp farming production in Golestan province were identified by collecting a questionnaire from 36 producers and experts in 2019. Ranking of problems through scoring method and due to the non-parametricity of statistics, tests of chi-square and Mann-Whitney U test were used in statistical analysis. According to the results of the research, problems such as shrimp disease and its aftermath, and the lack of post-larvae had a lot of problems in the product. Shrimp disease and its consequences, increase in input prices and lack of feed factory in the province were ranked first to third among 25 production problems, respectively. In some cases, producerschr('39') views differed from those of government experts. Experts in the province considered the lack of a provincial trade: union: and water restrictions and the flooding of swimming pools and producers to be the most serious problem due to the lack of larval substations and the lack of a feed factory in the province. Therefore, addressing the most important production problems such as controlling white spot disease and the necessary considerations to prevent its recurrence should be considered by the government.

This study was conducted to determine the effects of automatic and hand feeding on growth performance of “ Aspikutum” , a hybrid of Asp (Leucisicus aspius ♀ ) and Caspian Kutum (Rutilus frisii ♂ ) for six weeks. The study was carried out in two treatments each with three replications. Two hundred fish with mean initial weight of 19. 82 ± 2. 80 g were stocked in each circular fiberglass tanks containing 4000 liter of water. In hand feeding, fish were fed three times daily to apparent satiation and in automatic, feeding was adjusted with automated devices at the time of hand feeding treatment. Results showed that final biomass and voluntary feed intake were significantly affected by feeding methods (P<0. 05), but the final weight and length, gained biomass, body weight increase, specific growth rate, condition factor and feed conversion ratio were not significantly affected by feeding methods (P>0. 05). The present study revealed that because of monitoring of fish appetite and suitable effect on final biomass and feed intake of fish that fed by hand, this method is recommend in small scale farms for hybrid of Asp × Kutum.

Copper (Cu) is an essential micronutrient in animals for normal growth and development of bones, connective tissue, the heart and several other organs, since around 30 enzymes are known to use copper as a cofactor. The commercial diet should provide the essential amount of Cu, which depends on the physical and chemical properties of the form of the supplement in which the Cu is given in the diet. However, the feed industry still prefers CuSO4 for economic reasons. Thus this study was conducted to evaluate the effects of different sources of copper (Cu) on digestive enzymes activity and pathological alterations in goldfish, Carassius auratus. The five experimental diets were formulated to contain different levels of Cu-NPs (0, 3, 5 and 10 mg/kg) and 3 mg/kg CuSO4 and given to goldfish (initial average weight and length 7. 78 ± 0. 67 g and 5. 86 ± 0. 43 cm respectively) for 8 weeks. Intestinal protease and lipase activities increased and amylase decreased by Cu-NPs compared with the control group (p<0. 05). In this study, feeding goldfish with CuSO4 led to significant pathological alterations in intestinal tract. The overall result recommends adding 3 mg Cu-NPs per kg diet improve health and intestinal digestive where the same dose of CuSO4 induce intestinal tract negative impacts in goldfish. However, further studies are needed to explain the molecular mechanisms of Cu-NPs as well lower concentrations of CuSO4.

The purpose of this study was to determine the effects of pediococcus acidilactici and aloe vera powder on growth parameters, hematology and intestinal microbiota of Huso huso. After 2 week adaptation, 720 fry with average weight of 10. 63± 0. 51 g were allocated in 18 fiberglass tanks with 40 fish per each tank. The study was performed in a complete randomize design for 2 months with 6 treatment as follows: commercial diet(control, group 1), supplemented with 1. 5% aloe vera powder(group 2), 0. 1g probiotic(group 3), 0. 2 g probiotic(group 4), 1. 5% aloe vera and 0. 1 g probiotic(group 5) and 1. 5% aloe vera and 0. 2 g probiotic(group 6) per kg. Results showed that the best growth indices as final weight, SGR and FCR was obtained in combined treatments and treatment 4 which was significantly different with the control(p<0. 05). In terms of hematological and biochemical parameters of serum, the highest number of red and white blood cells, lymphocytes and albumin and total protein were obtained in combination treatments. In the end period sampling, the total number of intestinal bacteria and lactic acid bacteria in all treatments was significantly different with the control (p<0. 05). Based on the results, considering the positive effects of combined treatments on growth factors and no significant difference with treatment number 4, if the aim of breeding was to increase fish growth only, use of 0. 2 g of probiotic is recommended, but if both growth and the increase resistance of fish are considered, the use of combination treatment number 6 is recommended as an additive in the diet of fish.