نشریه علوم آبزی پروری ایران
سال ششم شماره 1 (بهار و تابستان 1397)

In the present study, the effect of enriched Dunaliella salina with zinc in 4 concentrations (0, 0.8, 1.6 and 3.2 mg L-1) was investigated on the growth, survival, and reproduction of Artemia parthenogenetica. Based on the results, on days 11, 17 and 21, the treatment of 3.2 mg L-1  and 0.8 mg L-1  had respectively the highest (7.07, 8.86 and 9.05 mm) and lowest (5.48, 7.06 and 7.25 mm) total length growth. In addition, survival rate decreased with increasing zinc content in the enrichment treatments and on days 11, 17 and 21. The lowest and highest survival rate was observed in the treatment of 3.2 and0.8 mg L-1, respectively. To determine the reproductive efficiency of A. parthenogenetica, the number of nauplii, cysts produced per female, encysted embryos percentage and the reproductive period of each female were investigated. The highest reproductive period (13.6 days) and nauplii production (43.64 nauplii) were significantly observed in treatment 3.2 mg L-1 (P>0.05). Based on the results, the highest and lowest encysted embryos percentage in A. parthenogenetica were observed in treatment 0.8 and 3.2 mg L-1, respectively. The results also showed that D. salina are well-enriched with mineral zinc and there was a significant increase in the total length growth. However, with increasing levels of enrichment, there was no increase in survival rates and all reproductive performance.

The diversity among Artemia species proves the importance of morphologic and morphometeric investigations. Morphologic studies not only help in identification of close species, but also help to study the effects of environmental factors on the species and to identify the most influencing parameters on the morphologic changes. In this research investigated we investigated the simultaneous effect of salinity and temperature on morphologic changes in two populations of Artemia urmiana and Artemia parthenogenetica. The hatching of the cysts, feeding of nauplii and their culture were performed according to standard conditions. The Artemia from both populations were cultured under sailities 60, 120 and 180 g/L at 15, 24 and 30°C for a period of 30 days. Later the morpholpgic characteristics of adult Artemia were measured using a steriomicropscope equipped with drwing tube and digitizer. During this research over all 15 morphologic indices were measured at nine combinations of salinity and temperature. The results of analysis of variance showed that the average of measured parameters in both populations were higher at 24-60 treatment. Dendrogram of the cluster analysis based on morphologic characteristics seprated the two populations. In general Artemia urmiana and Artemia parthenogenetica demonstrated more regular groupings based on temperature and salinity respectively. Based on the discriminant analysis the width of uterus, maximum distance between two compound eyes, length of telson, total body length, distance of 3rd segment to end of abdomen, width of head, length of left antenna, length of right antenna, width of 3rd abdominal segment, maximum diameter of left eye, number of setae on left furca, number of setae on right furca, maximum diameter of right eye, length of furca and length of abdomen respectively showed increasing effect on separating the two population.

In this study, Otolithes rubber fillets were treated by sea cucumber Holothuria leucospilota extraction and then they were vacuum packed. Packed fillets were refrigerated at 4 centigrade for sixteen days. As an evaluation, microbial tests every four days including counting total bacteria, Pseudomonas, Enterobacteriaceae and hydrogen sulfide-producing bacteria were done. The results declared that during the period, the sum of the total bacteria in all treatments has increased and the maximum value of this index was maintained at 12th day in all treatments. Furthermore during the storage period, the number of bacteria which produce hydrogen sulfide and Pseudomonas and Enterobacteriaceae, were significantly greater than samples which were treated by sea cucumber Holothuria leucospilota extraction. Interestingly, there were no bacteria in the samples that were treated by sea cucumber Holothuria leucospilota 2% extraction for first four days. Also Enterobacteriaceae weren’t found in 1% and 2% extraction treatments until the 8th day of storage and the bacteria producing hydrogen sulfide weren’t seen in 2%, 1% and 0.5% extraction treatment until 12th, 8th and 4th day respectively. Results indicate dramatically that sea cucumber extraction has a considerable impact on samples including maintaining quality and increasing storage time of fish fillets in cold conditions. Notably 2% extract was more effective than other extracts concentrations in increasing survival of fillets.

This study was designed to determine the cultivation potentials and protein value of giant gourami as a new edible species and compare it with common carp as a common species. In order to analysis the growth phase of the giant gourami in a monoculture system and compare it with common carp, fishes were purchased in the same weight range (5±0.27 and 5.02±0.17 g, respectively) and presented to concrete pools in the same conditions, two treatments with 3 replicates. Fish were fed with common carp commercial diet of for one year. Growth performance such as survival rate, weight gain, SGR, FCR and price index showed more optimal results (P<0.05) in common carp, but the protein efficiency and visceral index in giant gourami improved, significantly (P<0.05). Fillet and carcass yields were significantly higher in giant gourami (P<0.05). The essential amino acids such as arginine, histidine, lysine, threonine and tryptophan, and non-essential amino acids including alanine and serine were remarkably higher in giant gourami compared to common carp (P<0.05). Also, there was no significant difference in EAA/NEAA at two groups of fish (P>0.05). Overall, the results of this study showed that common carp in the same condition in concrete pools was more able to grow than giant gourami, but better values ​​for carcass yield and visceral index were obtained in giant gourami. In addition, according to the significant upgrading of the essential amino acids such as arginine, histidine, lysine, threonine and tryptophan and unnecessary amino acids including alanine and serine, and also the absence of significant differences in the EAA/NEAA at two species, due to the qualitative features and nutritional value of giant gourami, it can be considered as a valuable farmed fish.

The aim of this study was to investigate that the effect of commercial product of Multi-Behsil probiotic, including a mixture of several species of probiotic lactobacilli, bacilli, yeast and other probiotic microorganisms on growth and feeding performance in Oncorhynchus mykiss juveniles through the supplementation of diets. For this purpose, number of 600 fish juveniles with average mean weight 19.08±0.65 g were randomly introduced into 12 netting cages (size of 0.6×0.6×1 m with density of 50 fish per cage and placed in raceway concrete ponds). This experiment was conducted in a completely randomized design with a control group and three experimental treatments, M1, M2 and M3. In experimental treatments fish were fed with supplemented diets in levels of 200, 300 and 400 mg/kg of Multi-Behsil probiotic in diet for 45 days respectively. At the end of the trial, final weight and length, Average daily Growth, and Feed Conversion Efficiency showed significant differences in comparison with the control (P<0.05). There was no significant difference on specific growth rate, Thermal Growth Coefficient and Energy retention efficiency in comparison with the control group(P>0.05). While the crude protein (19.71%) and crude lipid (7.44%) of carcass in treatment of M3 had significantly increase (P<0.05) in comparison with the control group (crude protein 18.53% and crude lipid 7.17%). This study highlighted that the different levels of Multi-Behsil probiotic in rearing of Rainbow trout juveniles had different effects on growth and feeding performance in this fish.

Knowing on diversity and species composition of the phytoplankton provides insight on primary production and food webs in aquatic environments. In order to study of phytoplankton community of the Gomishan shrimp culture ponds, this study was carried out to determine diversity and frequency of phytoplankton species from May to October 2016. The samples were taken from surface waters of three point (near the inlet, middle and near the outlet) of six selected ponds by l-liter bottles. The results showed that phytoplankton community belong to 23 genus of 6 phylum including Bacillariophyta, Cyanophyta, Chlorophyta, Dinophyta, Cryptophyta and Euglenophyta. The community dominated by the genus Aphanotece, Chlamydomonas, Nitzschia and Pridinium. Two genus of Pridinium and Chlamydomonas had the highest frequency. Considering biodivercity index, Basilariophytahad the highest divercity. The Shannon diversity index and Menhinick richness were the highest in May and July, respectively, evenness index in July and August.

Artemia is known as one of the most important species of living food needed in many larval stages in many aquatic animals. In this study, the effect of different levels of hardness on three levels (200, 500 and 100) mg.L and various ratios of calcium to magnesium (100: 0, 80:20, 50:50, 20:80 and 0: 100) on The percentage of hatching, total length and mortality rate of A. franciscana were determined. The results of different levels of hardness and various ratios of calcium and magnesium on the performance of A. franciscana showed that increasing the level of hardness is caused a decrease in the average percentage of hatching (P≤0.05), so that in the 1000 mg.L treatment, the lowest mean hatching rate was recorded as 31±7. In addition, the best ratio of calcium to magnesium ratio was 50:50. On the other hand, the effects of hardness levels and calcium and magnesium ratios on A.franciscana mortality rate showed that with increasing hardness were increased and calcium and magnesium ratios had no effect on mortality rates. Based on the results, the ratio of calcium to magnesium in the hardness 500 mg.l, had highest amount of hatching 73.33±2.35. Also, the hardness increasing caused a decrease in the size of the nauplii length and increased mortality.

The aim of this research was to investigate the effects of various dry (commercial), live food (bloodworm larvae), diet (calf’s liver and heart) and combined diet (50% bloodworm larvae + 50% calf’s liver and heart) on fertilization rate, hatching percentage, survival rate of larvae and consecutive spawning intervals, as well as on growth factors and survival of infants until 60 years of age. Experiment with 4 groups including concentrate (A), bloodworm larvae (B), heart and liver of cattle (C) and the group consisting of 50% calf’s liver and heart and 50% larvae of bloodworm (D). In this experiment, 12 pair of angel fish broodstockes were used in twelve 60l glass aquaria.  Of roups were treated with more rations of the live food and mixed diet had the highest fecundity and survival rate of larvae than controls (A). The percentage of hatching was the highest in the combined diet group. The time interval between consecutive spawning in the group fed live food and mixed diet was significantly shorter than others. Also, it was found that in the groups fed live and mixed food, fry showed improvement of the growth parameters. The results showed that the presence of live food in ornamental fish diet can affect the reproductive capacity as well as the growth of its fry.

Heavy metals are considered as a hazardous group of water pollutants that have high potential of toxicity in aquatic organisms. The present study was conducted to investigate the absorption and accumulation of lead (Pb) in foot, mantle and gills of freshwater mussel, Anodonta cygnea. Bivalves were exposed to the sub-lethal concentration of 125 μg/L of Pb for 9 days and the basal Pb content in unexposed mussels, accumulation content and values of bioaccumulation factor (BAF) of the those  exposed were measured in days of 3, 6 and 9. There was no significant difference in basal levels of Pb in the studied organs. Pb contents in the exposed mussels were significantly (P<0.05) increased during exposure period in all organs. Accumulation levels on day 9 in foot (10.82±4.5 μg/g DW) and gills (10.02±1.69 μg/g DW) were significantly (P<0.05) higher than mantle (5.15±2.8 μg/g DW). BAF showed a significant increase (P<0.05) during the exposure period in all organs and BAF values for the mantle were significantly (P<0.05) lower than other organs. Based on the results, absorption and bioaccumulation of Pb as a non-essential element in A. cygnea has different trends in different organs.

This study aimed to investigate the effect of Carum copticum seedessential oil on inhibition the growth of Escherichia coli inoculated in minced of Cyprinus carpio during refrigerated storage (4˚C). Carum copticum seedessential oil with concentrations of 2, 3 and 4 µL/g were added in minced of C. carpio inoculated (10 3 CFU/g) with E. coliand after packing stored in refrogerator (4˚C). Chemical (PV, TBA and TVB-N) and microbial parameters (E. coli count, TVC and PTC) were measured at 24, 72, 144, 216 and 288 times (hrs). The PV, TBA and TVB-N values increased during storage in all treatments but this increase was lower in treatments containing C. copticum seedessential oil. TVC and PTC counts decreased with increaseing of C. copticum seedessential oil. The treatments containing C. copticum seedessential oil was inhibited the growth of E. coli and decreased E. coli number after 144 hrs. The concentration of 4 µL/g of C. copticum seedessential oil showed the greatest effect on chemical and microbial parameters. Thus it can be concluded that the C. copticum seedessential oil has antibacterial and antioxidant properties and recommended to preservative of fisheries products.