Iranian Scientific Fisheries Journal
Year:2013 | Volume:22 | Issue:2|Papers Count:14

This study was conducted to determine the effect of replacing fish meal with soybean meal on growth rate, feed conversion ratio and chemical composition of carcass, fillet and liver in juvenile stellate sturgeon (Acipenser stellatus). As in Treatments one (F), two (S1), three (S2), four (S3) and five (S4) 0, 10, 20, 30 and 40 percent of fish meal was replaced with soybean meal, respectively. Five isonitrogenous and isocaloric diets formulated containing 44 percent crude proteins and 4374 Kcal gross energy kg-1 diet. Individual body weights of fish were measured every three week. Fish were sampled randomly from each treatment for whole body, fillet and liver proximate analysis. Based on the results, weight gain (WG) and feed conversion ratio (FCR) had significant difference among the treatments (P<0.05), as S3 and S4 diets had significantly weakest performance than any of other diets (P<0.05). FCR in fish fed on F and S1 diets were significantly higher than fish fed on other diets, while statistical significant differences were observed between S2 with two other treatments. Significant differences were found in carcass protein, lipid, and moisture content in fish fed on diets with different soybean meal levels (P<0.05), but ash content have not significant difference among the diets (P>0.05). Significant differences were found in fillet lipid content (P<0.05), but protein, moisture and ash content did not significant difference (P>0.05). Liver proximate composition of fish did not significant difference (P>0.05).

Fermented sausage is a favorite kind of meat-product that has allocated great proportions of meat consumption in the world. For the first time in Iran in this study the production of Fermented sausage from minced meat of common carp was assessed by means of lactic acid bacteria at different incubating temperatures as 15, 25, and 35°C. To prepare the fish sausage, common carp mince was grounded and mixed with NaCl (3%), glucose (3%) and lactic acid bacteria at 5 log CFU/g and afterward were incubated for 48 h. During the incubation of fish sausage, microbiological tests, moisture and protein content, and TVB-N were measured. According to the results, the higher temperature of 35°C stimulated the rapid growth of lactic acid bacteria, resulting in a rapid decline in pH, and consequently suppressed the growth of pseudomonas, Micrococcaceae and Enterobacteriacea.

Microalgae as a source of valuable compounds such as fatty acids are isolated from the natural environments and their mass production with high nutritional value is one the necessities of many hatcheries. The present study aimed to determine the effects of enriched daphnia with microscopic algae on some growth indices and survival rate of Persian sturgeon (Acipenser persicus) larvae. Chlorella vulgaris and Scenedesmus dimorphus were purified and cultured. Then, Daphnia longispina was fed microalgae including Chlorella vulgaris and Scenedesmus dimorphus enriched with Docosahexaenoic acid (DHA). The microalgae density to enrich daphnia was estimated at 5´107 cells mL-1. Three treatments with three replicates and a control group were considered in this study. A total of 30 Acipenser persicus larvae were allocated to each sixty liters tank. Experimental fish were fed daphnia enriched with Chlorella vulgaris (treatment 1), daphnia enriched with Scenedesmus dimorphus (treatment 2) and daphnia enriched with Chlorella vulgaris and Scenedesmus dimorphus (at the rates of 50%) (Treatment 3). Persian sturgeon larvae in the control group were fed like VNIRO stage from daphnia caught in pond. Larvae were fed 30% of body weight per day for four times. During the experimental period, water temperature, dissolved oxygen concentration and pH ranged between 18-24°C, 5.8-7.2 mg l-1 and 5.6-8.2, respectively. The minimum (219±98.4 mg) and maximum (315.16±140.8 mg) mean (±SD) weights were observed in the control group and treatment 3, respectively. The results obtained from the body weight increase (BWI %) revealed that there were significant differences between treatment 3 and other treatments. Highest (4.6±1.13% day-1) and lowest (5.5±1.24% day-1) mean (±SD) specific growth rates (SGR) were recorded in fish fed the control group and treatment 3, respectively. Lowest (68%) and highest (85%) survival rates were recorded in the control group and treatment 3, respectively.

In this study phytoplankton were used as a water quality index in agricultural sewage for feasibility study of aquaculture in Ahwaz and Khorramshahr region. Monthly sampling was done in 6 stations during one year period (2008-2009).34 phytoplankton genuses were identified. The most frequent classes were Bacillariophyceae (diatoms), Cyanophyceae, Chlorophyceae, Dinophyceae. The water flow of drainage channel had inverse relationship with phytoplankton density. Diatoms were present in all stations. Palmer index suggested that station 2, 5, 6, 3, 4 had the highest rate of pollution respectively and station 1 was relatively polluted. The stations of 1, 2, 5, 3, 6, 4 had the highest value of useful phytoplankton index for fish growth.

This research was carried out to study some physiological responses of mudskipper (i.e., Boleophthalmus dussumieri) as a biomarker Poly Aromatic Hydrocarbons (PAHs). Fish specimens were obtained 5 stations (Arvand, Jafari, Zangi, Samayeli, Bahrakan) along north western coast of the Persian Gulf (Khuzestan Coast). PAHs concentration was measured by HPLC method. Lysosomal membrane change was measured by NRR time method and stability of red blood cell membrane was evaluated by EOF test. Total PAH concentrations in the sediments and the liver tissue ranged between 113.50-3384.34 ng g-1dw, 3.99-46.64ng g-1 dw, respectively. Highest PAHs pollution was found at Jafari while the lowest was detected at Bahrakan, with significant between these 2 stations. Values of mean RT of the dye ranged from 34 (for the blood samples of mudskipper collected from Jafari site) to 78 minutes (for the blood samples of mudskipper collected from Bahrakan). Preliminary results showed a significant difference among stations except between Arvand and Zangi. Osmotic fragility curves indicated that erythrocytes collected from mudskippers at Jafari were the most fragile followed by Zangi>Arvand>Samayeli>and Bahrakan. The results suggest that lysosomal membrane change and red blood cell membrane stability in B. dussumieri could be extended as a biomarker of oil pollution in marine biomonitoring programs.

Nudibranches are the largest group of Hetrerobranches, (a sub-branch of Opisthobranchia) and are widespread and cosmopolitan species. They vary in shape and colors and occur in all waters from intertidal to deep sea zones and from polar to the tropics regions. Nudibranches are subdivided in two main groups including Anthobranchia and Cladobranchia. In the present study, based on morphology the svudied species was identified as Goniobranchus annulatus that belong to Anthrobranchia group. In molecular analysis the sequences of the partial mitochondrial COI gene of Goniobranchus annulatus species from Iran with 15 similar sequences of nudibrnaches from genbank were compared. Phylogenetic based on Neighbor_joining analyze showed a monophyly relationships between families of nudibranches and also revealed that Goniobranchus vibratus is a sister taxa to the Gonidbranchus annulatus from Iran Goniobranchus annulatus with 100% bootstrap support.

In this study, the effects of Rosemary and Zataria extracts on three different treatments in frozen Silver carp minced were studied in normal packaging. Therefore, a control and three treatments were defined: Treatment 1 - Control: frozen meat packaged in conventional Treatment 2: Frozen Silver carp minced+Zataria 300mg/kg in normal packaging Treatment 3: Frozen Silver carp minced+Rosemary 200mg/kg in normal packaging Treatment 4: Frozen Silver carp minced+Rosemary compound (100mg/kg) and Zataria (100mg/kg) in normal packaging After quick freezing of samples in the spiral freezer by individual quick freezing method, to maintain the cold temperature (-18)°C were transferred. For six month, Sampling and measurements to determine the fatty acid profile of the zero phase beginning in the first month and then every ten days, and 15 days in the second month of the third month after the monthly test. Identifying, defining and measuring the fatty acid profile by gas chromatography were performed. In this study, levels of both saturated and unsaturated fatty acids in three experimental and one control were identified as follows: A: SFA: (Saturated Fatty Acid): Meristic C14: 0/ Palmitic C16: 0 /Hepta decaenoic C17: 0 / Stearic C18: 0 / Arashidic C20: 0 B: (MUFA Mono Unsaturated Fatty Acid): Palmitoleic C16: 1-W7 / Oleic C18: 1-W9 /Gadoleic C20: 1 - W9 C: (PUFA Poly Unsaturated Fatty Acid): Linoleic C18: 2-W6 /α-Linolenic C18: 3-W3 D: (HUFA High Unsaturated Fatty Acid): Arachidonic C20:4 - W6 Eicosa panta enoic acid C20: 5- EPA/W3 Docosa hexa enoic acid C22: 6-DHA/W3. Results of this study was to determine keep frozen fish meat containing extracts of Zataria and Rosemary in freezing conditions, stability of different types of fatty acids, mono unsaturated fatty acids, poly unsaturated fatty acids, high unsaturated fatty acids, So that none of the fatty acids measured, were not observed increase or decrease Changes over time while maintaining the oxidation of fatty acids is minimized. The results obtained from the profile of fatty acids and their related indices and statistical tests show the treatment contains Rosemary extract show greater stability than thyme during storage (18°C). According to studies, frozen minced fish meat treated with extracts of Rosemary, was used until the end of the storage period.

The aim of the present study was to determine the impact of replacing the fish oil by alternative lipid sources in diets for rainbow trout (Oncorhynchus mykiss) on growth, fatty acid profiles of muscle. Five isonitrogenous and isoenergetic semipurified diets were formulated containing 100% rice bran oil (RBO), 100% linseed oil (LO), 100% Soybean oil (SO) and a 1: 1: 1: 1 rice bran, linseed, soybeen and fish oil mixture (MX) were compared to a pure fish oil (FO) diet. The diets were fed to apparent satiation twice a day to triplicate groups of 30 rainbow trout with an initial weight of 90g for 15 weeks at 12°C.At the end of the experiment, fillet samples were collected from fish for the measurement of fatty acid profile and fillet composition. Fish fed the FO diet had the highest weight gain over the experimental period (280.28 g), However no differences in growth rate and CF were observed across diet groups. Feed conversion ratios (FCR) ranged from 1.12 to 1.24. Significant difference in FCR was found in the group fed an FO diet. The fillet lipid concentrations and fatty acid composition of the fish were significantly affected by the experimental diets. Fish fed the FO diet contained significantly lower lipid levels (20.18%) than those fed the 4 other diets. The highest level of n-3 PUFA concentrations were recorded in fish fed the LO diet (21.8) with significant difference than other diets and the lowest were in those fed the RBO diet (7.84). Fish fed the SO diet contained significantly higher level of n-6 PUFA concentrations (31.72) than other diets and the lowest were in those fed the FO diet (19.15). Fish on the FO diet had a significantly greater percentage of DHA (10.10%) in muscle tissue compared with fish on all other diets and the lowest was in those fed the RBO diet (2.81%). However, the highest level of eicosapentaenoic acid (EPA) concentrations was recorded in fish fed the SO diet (1.84%) and the lowest in those fed the diet (0.67%). This study showed considerable reductions (about 3-fold) in the n-3/n-6 ratio when FO in the fish diet was replaced by rice bran and soybean oils, which may be extremely negative from a nutritional point of view. In other hand linseed oil had the highest n-3/n-6 ratio (0.91) that was comparable with fish oil n- 3/n-6 ratio (0.89). The results in this study imply that an appropriate mix of vegetable oils and FO can replace the sole use of FO in fish feeds.

In the present study, accumulation of manganese, cadmium, zinc, iron and copper in the commercially fish species (silver pomfret and tiger tooth croaker) caught from Bandarabbas coasts at 2010 was measured and the risk of daily intake of them in Hormozagan urban population was estimated. The average concentrations (μ/g dry weight) of manganese, cadmium, zinc, iron, and copper in the muscle tissue of silver pomfret were 1.248, 0.217, 14.444, 2.397 and 3.300, respectively, while the concentration of them in tiger tooth croaker were 1.009, 0.403, 12.564, 4.467 and 2.366, respectively. According to fish consumption rate, urban populations of the province were divided into four groups, low, medium, high and very high. The target hazard quotient (THQ) in each group calculated separately. The THQ of all groups were much lower than 1 in the two fish. The results showed that urban populations of the province have not any risk due to accumulation of the studied heavy metals.

In the present study, accumulation of manganese, cadmium, zinc, iron and copper in the commercially fish species (silver pomfret and tiger tooth croaker) caught from Bandarabbas coasts at 2010 was measured and the risk of daily intake of them in Hormozagan urban population was estimated. The average concentrations (μ/g dry weight) of manganese, cadmium, zinc, iron, and copper in the muscle tissue of silver pomfret were 1.248, 0.217, 14.444, 2.397 and 3.300, respectively, while the concentration of them in tiger tooth croaker were 1.009, 0.403, 12.564, 4.467 and 2.366, respectively. According to fish consumption rate, urban populations of the province were divided into four groups, low, medium, high and very high. The target hazard quotient (THQ) in each group calculated separately. The THQ of all groups were much lower than 1 in the two fish. The results showed that urban populations of the province have not any risk due to accumulation of the studied heavy metals.

Diplostomum spathaceum is a digenean parasite with an indirect life cycle. Its mature stage lives in gull's intestine, cercariae in snails (Lymnaeidae) liver and metacercariae stage in piscine, amphibian, and mammalian eyes. Notice that penetration of cercariae into skin and eye cause lesions which cause susceptibility to secondary infections, appetite loss due to infections, blurry vision, and disability in hunting and feeding on fish. It, therefore, plays an important role in aquatic health. During this study, prevalence of Diplostomum spathaceum infectious in 240 introduced and endemic fishes of water resources in West Azerbaijan province were studied from spring 2008 to winter 2010. The results indicate that 58/30 % of fish (140 fish) showed infestation with this parasite which presents a high rate of infestation in the fishes in these water resources.