مجله علوم شیلاتی ایران (انگلیسی)
سال:1391 | دوره:11 | شماره:2 |تعداد مقالات:19

An analysis of eight microsatellite loci in 90 individuals was performed to define the genetic structure and variability of three estuarine populations of Coilia mystus: 30 individuals each collected from Chang Jiang River (Yangtze River) estuary-CJ, Min Jiang River estuary-MJ, and Zhu Jiang River (Pearl River) estuary-ZJ. The results showed polymorphic information contents (PIC) of 0.78, 0.77, and 0.64 in CJ, MJ, and ZJ, respectively. The mean observed number of alleles (Na) ranged from 7.38 to 11.88. The mean observed and expected heterozygosities ranged from 0.09 to 0.21 and from 0.68 to 0.81, respectively. The ZJ population was least polymorphic. Highly significant deviations from Hardy-Weinberg equilibrium, mostly due to deficits of heterozygote, were found in these three populations. Pairwise FST and Reynolds' distance indicated that the three estuarine populations were genetically distinct, in accordance with the principal component analysis (PCA) and the Bayesian model-based clustering algorithm analysis. The results showed that pairwise genetic differentiation among these three estuarine populations were relatively high, with possible divergence to subspecies level. This study provides microsatellite DNA evidence for assessing the genetic distinctness of C. mystus populations and will benefit fishery resource management and sustainable utilization of C. mystus.

Dunaliella salina, a green microalga, has been consumed as food and medicine for a long time.The anti-oxidant and anticancer effects are related to more production of b- carotene under stress conditions compared with normal circumstances. The scope of this study was survey of anticancer effect of the ethanol extract of Dunaliella salina algae under stress(EDSS) and normal (EDSN) conditions on death rate of skin carcinoma cell line A431 by MTT [3-(4,5-dimethylthiazol-2-y1)-2,5-diphenyltetrazolium bromide] method in vitro. Our results showed that the b-carotene amount in stress situation was 1.46 times more than in normal condition.The cytotoxic effect of EDSS exposed to 6.25, 12.5, 25, 50, 100 mg/ml in 6, 24, 48 h which was performed by MTT assay showed that there was a significant difference in the various time except in 6 h in both conditions. The results of compared death rate of A431cells exposed to various concentrations of EDSS and EDSN presented significant difference in 6, 24, and 48 h after exposure. The LC50 of EDSS in 24 and 48 h were 15.4 and 0.4 mg/ml , respectively and 478.6 and 46.4 mg/ml for EDSN.

Sea Urchin is one of the most useful tools in developmental biology studies because this organism has the simplest kind of developmental stages. We aimed to determine developmental stages and timetable of Echinometra mathaei embryo (the species of Persian Gulf). The spawning of E. mathaei was induced by 0.5M KCl injection (1ml) into the coelomic cavity. After fertilization, embryos were placed in beakers and were incubated at 29°C and a salinity of 39 ppt until embryos reached the pluteus stage. The developmental stages of embryos and the timing of each stage including cleavage, morulae, blastula, gastrula, prism and pluteus larvae were studied under the microscope. Our results showed that after 30 hours from fertilization time, the embryos developed to pluteus larvae. E. mathaei had the shorter development time in comparison to the other Sea Urchin species. Therefore, it may be appropriate as a model organism in biological researches.

The distribution and localization of acid and neutral mucins in various cells lining the olfactory epithelium of Cyprinus carpio have been studied histochemically by employing the PAS-AB technique. Variations in the localization of protein in different cells lining the olfactory epithelium have been correlated with the functional significance of the region concerned. Intense localization of the silver stain in the surface of the olfactory epithelium as well as in the central core confirms the presence of different types of neurons. The localization and functional variations of alkaline phosphatase (ALPase) and adenosine-tri-phosphatase (ATPase) in the cells lining the olfactory epithelium of C. carpio have been discussed.

In this study, the malondialdehyde (MDA) levels in the muscle, liver and kidney tissues and the antioxidant vitamin (A, C, E) levels in the muscle tissue of juvenile rainbow trout were investigated under different oxygen levels (3.5 mg O2/l, 4.5 mg O2/l and 7 mg O2/l) at the end of the 8 hour trial. Fish (initial weight and length, 30.19±2.2 g and 13.15±0.22 cm, respectively) were distributed into 9 fiberglass rectangular tanks. The highest MDA level of all tissues was obtained in 3.5 mg O2/l (p<0.05). Different oxygen levels did not affect muscle vitamin A concentration statically (p>0.05). But the highest muscle vitamin C and E concentrations were obtained in 7 mg O2/l. (p<0.05), followed by 3.5 mg O2/l, while the lowest muscle vitamin C concentration was obtained in 4.5 mg O2/l. (p<0.05).

Fish Protein Concentrate (FPC) is a healthy, sustainable and high nutritive product that produced from fish and protein and other nutrients are more concentrated than in the fresh fish. The aim of this research is to study the sustainability of FPC produced from Kilka (combination of three Caspian Sea Kilka species, Clupeonella engrauliformis, C. grimmi and C. cultriventris which were not identified and processed separately) in VP (Vacuum Packaging) and MAP (Modified Atmosphere Packaging) at different temperatures during six months of storage. According to result of chemical analysis performed, protein content was evaluated 91.2%, lipid 0.5%, ash 3.6%, moisture 2.3%, TVN 10 mg/100 g and peroxide 5 meq/kg in the produced FPC before packing. Amino acids and fatty acids were also determined. Lipid amount in FPC after 6 months at 35°C in VP changed from 0.50 to 0.45 and in MAP (combined of 60% CO2, 30% N2 and 10% O2), decreased from 0.50 to 0.36. It was also detected that increase in temperature leads to more decrease in lipid content but it was not significant (P>0.05). Protein content of FPC has changed from 91.2% to 73.6% during six months at 35°C in VP and 69.4% in MAP. But at 5°C, protein contents were changed from 91.2% to 88.4% and 81.2% in VP and MAP, respectively; these changes were significant (P<0.05) but the decrease in MAP was again more than VP.

Euglenophyte bloom is a common problem in most of the aquaculture ponds in Bangladesh. In the present study we conducted an experiment to control euglenophyte bloom for achieving better fish production using duckweed (Lemna minor) and lime. The experiment was carried out using four treatments, i.e., ponds were supplied with duckweed (T1), lime treatment (T2), both duckweed and lime (T3) and without supply of duckweed and lime (T4). Rohu, catla, mrigal, silver carp and silver barb were stocked and their gut contents were analyzed monthly. The ranges of water quality parameters were analyzed within the productive limit during the experimental period. The mean abundance of euglenophyte was significantly highest in T4 (17.62 ± 1.97 x 104 cells/L), followed by T2 (2.96 ± 0.20 x 104 cells/L), T1 (1.94 ± 0.35 x 104 cells/L) and T3 (1.53 ± 0.42 x 104 cells/L). Gut content analysis revealed that considerable amounts of euglenophyte were consumed by silver carp and silver barb, but not preferred by rohu, catla and mrigal. The gross yields of fish were 2133.37, 1967.76, 2816.52 and 1725.62 kg/ha/5 months in T1, T2, T3 and T4 respectively. The highest fish production in T3 and lowest fish production in T4 indicated the use of duckweed and lime is economically sustainable for controlling euglenophytes bloom, maintaining water quality and getting higher fish production.

The concentrations of Cd, Pb, Ni and Hg were determined in gill, liver and muscle of Barbus xanthopterus in down streams of Karoon and Dez Rivers during summer 2009. Heavy metal concentrations varied significantly, depending on the types of the tissue in fish species. The levels of heavy metals such as Cd, Pb, Ni and Hg in the Barbus xanthopterus of Karoon River were higher than in Barbus xanthopterus of Dez River (P<0.05). In Karoon and Dez Rivers, the concentrations of Cd, Pb and Ni were in the sequence gill>liver>muscle. The concentration of Hg in Karoon River was in the sequence liver> gill> muscle but, in Dez River, it was in the sequence liver> muscle > gill. Among heavy metals (Cd, Pb, Ni and Hg), the accumulation of Pb was more than other heavy metals in fish (P<0.05). In both rivers, the accumulation of heavy metals in muscle of fish was higher than the world health organization (WHO) standard.

The purpose of this study was to investigate the therapeutic effects of natural products like propolis on biochemical and hematologic parameters in carp (Cyprinus carpio, Linnaeus 1758) exposed to arsenic. In this study fish were exposed to 0.01 mg/L arsenic and 10 mg/L propolis for seven days. Our results indicated that triglyceride, urea, total cholesterol, cobalt, ALT (alanine amino transferase), AST (aspartate amino transferase), LDH (lactate dehydrogenase) values increased when exposed to arsenic (P<0.05) but reduced by combination of arsenic and propolis (P<0.05). Granulocyte, erythrocyte, hemoglobin, hematocrit values were decreased by use of arsenic in comparison to control group. These parameters increased in arsenic+propolis group (P<0.05). In addition levels of leucocyte, agranulocyte, MCV (mean corpuscular volume), MCH (mean corpuscular hemoglobin) and MCHC (mean corpuscular hemoglobin concentration) increased in the arsenic group (P<0.05) and decreased in arsenic+propolis group (P<0.05). We can say that propolis can improve biochemical and hematologic functions of common carp blood, after being exposed to arsenic.

In this study Amplified Fragment Length Polymorphism (AFLP) was applied to species identification of bester hybrids. Hybrids identification was performed by comparison of electrophoresis profiles with parental species. The simultaneous occurrence of diagnostic bands fixed in the parental species, genetic distance and identification and cluster analyses (UPGMA) allow a correct identification. We used 8 primer combinations (Eco+3, Mse+4) and a total of 250 bands (size range 40-1000 bp) were generated. Primer combinations of (E-AAT, M-CGAT) and (E-AAG, M-CGAT) produced diagnostic bands in hybrids and parental species. Moreover, the results of genetic identification showed that Bester hybrids are more similar to beluga (Huso huso) (0.68) in comparison with sterlet (Acipenser ruthenus) (0.45).The results suggested that this technique could be suitable for precise identification of species and inter-generic hybrids like bester.

The consumption of sea-foods especially different kinds of fish has been increased in many countries such Iran in recent years (Akhonzade Basti et al 2006, Feldhusen, 2004). However, there is substantial evidence that fish and seafood are high on the list of foods associated with outbreaks of food borne diseases (Huss, 2003). Safety of fish products and their quality assurance is one of the main problems of food industry today. The presence or absence of foodborne pathogens in a fish product is a function of the harvest environment, sanitary conditions, and practices associated with equipment and personnel in the processing environment (FDA, 2001; Huss, 2003). The handling of fish products during process involves a risk of contamination by pathogenic bacteria such as V.parahaemolyticus and S. aureus, causing foodborne human intoxication (Shena et al., 2007); These bacteria are salt-tolerant and therefore can contaminate all cured preparations such as cold smoked fish, caviar and fish-based preserves. Staphylococcus is not found in the normal microflora of fish.

Fish reared under intensive culture conditions very often face stressful adverse conditions which either do not exist in nature, for example living in extremely high stocking densities, or they are quite unlikely, for example increased water ammonia levels (Huntingford et al. 2006).Nitrate (NO3-) which is the ionized form of nitric acid (Cheng and Chen, 2002) and salts, like sodium nitrate, are readily soluble in water and completely dissociated. It is produced by a two-step process called ‘nitrification’ (Hargreaves and Tucker, 2004). During this process, ammonia, which is either excreted from fish or produced by the decomposition of the organic matter in the water, is first oxidized to nitrite (NO2-) and subsequently to nitrate (NO3-). The nitrification rate can be affected by many factors such as water temperature and available diluted oxygen (Hargreaves and Tucker, 2004).