Iranian Journal of Fisheries Sciences
Year:2016 | Volume:15 | Issue:2|Papers Count:26

The aim of this research was to determine the concentration of cadmium (Cd) and lead (Pb) in the muscle and liver tissues of rainbow trout(Oncorhynchus mykiss) in Hamedan Province (west of Iran) cold water fish farms, and compare the results with the FAO/WHO guidelines. Heavy metal concentrations were determined from the three randomly selected fish farms by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) method. Concentration of heavy metals were detected to be high in rainbow trout during dry season. Concentration of Cd and Pb in the muscle and liver tissues were 3.67mg/kg and 12.82mg/kg, respectively. However concentrations of these two heavy metals were within the standard limits set and recommended by FAO/WHO, indicating that the rainbow trout meat raised from this region is safe for human consumption.

Arowana (Osteoglossum bicirrhosum) and cat fish (Hypostomus plecostomus) are two species of ornamental fishes which are mostly imported to Iran. Monogenea are plathyhelminthes which can dominantly infest the fish skin and gills with high host specificity. In this research, 35O. bicirrhosum and 50 H. plecostomus with clinical signs were collected from different ornamental fish markets in Semnan, Iran and transferred alive to the Lab. Fish skin and gills were examined for monogenean infestations. No monogenea was observed on the skin specimens, butGonocleithrum cursitansand Unilatus unilatus infested 54.28% and 74% of gills in O. bicirrhosum and H. plecostomus, respectively. This is the first report of both G.cursitans and U. unilatus in Iran.

The current study was done to investigate the preclinical safety and toxicology of Althaea officinalisextract as naturopathic medicine in common carp (Cyprinus carpio).Specimens were treated with 0 (control), 2.5, 5 and 10 g of marshmallow extract for 45 days. Plasma biochemical parameters were measured after 15 and 45 days. Total protein, albumin and globulin levels (p<0.05) were significantly higher in the fish fed with 10 gA. officinalis extract than that in control groups on day 45. Although, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activities significantly decreased (p<0.05) in fish fed with A. officinalis extract on day 15. The use of theA. officinalis extract (10 g) led to a significant increase in AST, lactate dehydrogenase (LDH) and ALP activities and cholesterol levels on day 45 (p<0.05) and a significant decrease in plasma glucose and cholesterol levels on day 15 (p<0.05). There was no significant difference in glucose levels and creatine kinase (CK) activity between all treatments and the control group on day 45 (p>0.05). During the experimental period, triglyceride levels noticeably decreased in fish fed with 2.5 g ofA. officinalis extract (p<0.05). Although, administration of marshmallow extract up to 5 g per kg of feed did not show any side effect on fishes, the use of theA. officinalis extract (10 g) led to cytotoxicity and modifications in blood biochemical parameters of fish. Therefore, we recommend the use of the lower concentrations than 10 g A. officinalisextract in prospective clinical studies.

The application of new probiotics is a good strategy in the biological control of infectious diseases in aquaculture. Approximately 100 marine actinobacteria isolates were obtained from 10sediment samples of shrimp farms. Heat treatment of sediment samples resulted in a selective reduction of the non actinobacterial heterotrophic microflora. Starch nitrate agar medium exhibited more efficacy than glycerol arginine agar medium for isolation. Twenty seven percent of actinobacterial isolates showed antagonistic activities against pathogenicVibrio spp. All the antagonistic isolates showed the typical morphology of genusStreptomyces. Exoenzymatic activity screening showed that 44 %, 26%, 37% of antagonistic isolates represented amylase, lipase and protease activities, respectively. MNM-1400 strain exhibited highest antagonistic and exoenzymatic activity. The pathogenicity experiment revealed that MNM-1400 strain did notcause disease in Litopenaeus vannamei larvae. Extraction of produced antibacterial compounds by MNM-1400 strain showed that the active constituent didn’t have non polar property. Morphological, physiological and biochemical identification confirmed that MNM-1400 strain belonged to the genus streptomyces.Phylogenetic analysis by 16S rRNA gene sequencing showed a high similarity between MNM-1400 strain andStreptomyces californicus (similarity: 99%).These results suggest thatthe MNM-1400 strain can be considered as a potential probiotic in aquaculture.

A feeding trial of ten weeks was conducted to evaluate the effect of microbial phytase supplementation on mineral digestibility inLabeo rohita fingerlings fed on canola meal-based diets. The experiment consisted of a reference diet and a basal diet. The reference diet was prepared according to the requirements ofL. rohita and was used as a standard diet. The basal diet was made by replacing 30% reference diet with canola meal which was used as the test ingredient in this experiment. Seven test diets were prepared by spraying graded levels (0, 250, 500, 750, 1000, 1250 and 1500 FTU kg-1) of phytase on canola meal-based basal diet to assess the optimal dose required to achieve best performance in terms of mineral digestibility coefficients. Chromic oxide was incorporated as an indigestible marker in the diets. Phytase supplementation significantly increased mineral digestibility inL. rohita fingerlings at 750 FTU kg-1 followed by that at 1000 FTU kg-1 as compared to the reference diet. The results of our study suggested that phytase supplementation in canola meal-based diet at the rate of 750 FTU kg-1 is optimum to release sufficient chelated minerals in L. rohita.

The aim of this work was to study the effect of sodium chloride replacement with potassium chloride on quality changes of hot smoked Kilka during storage at ± 4oC. To achieve this, after initial preparation, samples were exposed to brining process in two salts. This study was designed in two stages: in the first stage, different levels of salt replacement were used to select the best smoked treatment based on sensory test. In this stage, treatments were as: control (100% of NaCl), treatment 1 (75%NaCl/25%KCl), treatment 2 (50% NaCl/50%KCl), treatment 3 (25%NaCl/75%KCl), treatment 4 (100% of KCl). Samples were processed at slow and fast speed smoking for about 4 h, cooled and then tested by test panel. In the second stage, biochemical changes of selected treatment (treatment 1) were compared with control samples during storage at ± 4oC for 15 days. There were no differences (p>0.05) in content of fat, moisture, ash and TBA indices between control and treatment1. Protein levels and salt intake were significantly (p<0.05) increased while the TVB-N and PV indices decreased in treatment1. The results indicated that 25% sodium replacement with potassium is desirable for this product.

Seventy Two sediments from four stations (Anzali, Tonekabon, Noshahr and Amirabad), located in Caspian Sea-Iranian coast were examined on the basis of Pfractionation in autumn and winter of 2013-2014. Several forms of the phosphorus in sediment were separated and extracted according to sequential extraction method. Then the extracted phosphorus in each fraction was determined by UV–Vis spectrophotometry. In addition, Total concentrations of Ca, Fe and Al in sediment fractions were also measured by Atomic absorption spectroscopy. In autumn the rank order of P-fractions was: Ca-P>Residual-P>BD-P>Al-P>loosely-P and in winter it was: Ca-P>BD-P>Residual-P>Al-P>loosely adsorbed-P. In both season the loosely adsorbed phosphorus (NH4Cl–P) represented<1% of the sedimentary inorganic phosphorus, while the reductant phosphorus (BD–P) ranged from 2.7 to 4%. The calcium bound phosphorus (Ca-P or HCl–P) showed considerable contribution (89-91%) to the sedimentary inorganic P-loads. The metal oxide bound phosphorus (Al-P or NaOH–P) was 1.2-1.5% and Residual-P was 2.3-4.5%. Concentration of BD- P increased with increasing depth in all stations and the concentration of other fractions increased in most stations. Sampling seasons had significant effect on variance of most P-fractions and other sediment features. TP and BD-P were positively correlated with Fetot (p<0.05).

This study represents a large-scale population genetic analysis of the stellate sturgeon, Acipenser stellatus, in the Caspian Sea. In total, 192 samples of adult stellate sturgeon were collected from four commercial catch stations in the Northern (Volga and Ural Rivers) and Southern Caspian Sea (estuary of Sefidrud and Gorganrod Rivers-Iran).Fifteen sets of microsatellite primers developed from lake sturgeon (Acipenser fulvescens) and shovelnose sturgeon (Scaphirhynchus platorynchus) were tested on genomic DNA. Ten primer sets (LS-19, 34, 54, 68, Spl-105, 104, 163, 170, 173, 113) revealing polymorphic loci were used to analyze the genetic variation found in adults of the stellate sturgeon populations. Analyses revealed that the average number of alleles per locus was 13.05 (range 8 to 18 alleles per locus in regions, Ne=7.86). All sampled regions contained private alleles. The average observed and expected heterozygosities were 0.665 and 0.862, respectively. Deviations from Hardy-Weinberg equilibrium were seen in most cases. Average of Fis, Fit and Nm were 0.230, 0.261 and 7.498, respectively. Pairwise PopulationFST Values ranged from 0.019 to 0.035. FST, RST, and gene flow estimates in AMOVA indicated significant genetic differentiation among and regions, indicating that the populations were divergent. The genetic distance between populations indicates that the genetic difference among the studied populations is pronounced. These results together with highly significantRST of genotypic differences between these pairs of collections support the existence of different genetic populations along the Caspian Sea coast.

In this research, antagonistic activity of twoBacillus species isolated from digestive tract of marine fish and culture pond of sea cucumber was studied. The inhibitory activity ofBacillus spp. isolates against some common pathogenic bacteria of fish was assessed using the agar diffusion method. The strain ofB. subtilis G024 exhibited antimicrobial activity againstVibrio anguillarum, V. harveyi, V. vulnificus, Streptococcussp. and Staphylococcus aureus; the isolate of B. amyloliquefaciens N004 inhibited growth inV. anguillarum, V. campbellii, V. vulnificus, V. parahamolyticus, Edwardsiella tarda, Streptococcus sp., B. cereus. Scanning electron microscopy (SEM) investigation of indicator bacteria showed that cell morphologies were strongly affected by the cell-free supernatant of the twoBacillus spp. isolates. It is determined that the culture filtrates contained inhibitors against growth of some pathogenic bacteria with different degrees of inhibition, although none of the culture filtrates could inhibit the growth ofV. fluvialis, V. alginolyticus, V. splendidus. Based upon these characteristics, both of the antagonisticBacillus spp. isolates could be the potential probiotics used in the aquaculture production.

Sago starch is a locally grown and produced starch resource in Malaysia. In this study, corn starch to sago starch ratios (CS: SS) of 0: 20, 5: 15, 10: 10, 15: 5 and 20: 0 were included in feed mixture to contain 20% starch and produce five isonitrogenous and isocaloric (30% crude protein and 16.7 kJ/g, respectively) tilapia Oreochromis sp. diets. Diets were preconditioned to contain 40% moisture and extruded using a single-screw extruder at screw speed of 120 rpm using three different temperature profiles (I 60-100-140-180oC; II 60-100-120-160oC; and III 60-120-120-180oC). Effects of these factors were evaluated on physical properties of extrudates including expansion ratio, bulk density, water stability, floatability, sinking velocity and durability. From the results, different temperature profiles and CS: SS had significant effects (p<0.05) on expansion ratio and floatability. Sago starch performed as a good binder as it gave higher percentage of water stability and pellet durability. The mixture with 10: 10 of corn to sago starch extruded using temperature profile II (60-100-120-160oC) produced the best extrudates with desirable physical properties.

This study was performed to compare the efficiency of six microalgae namely Dunaliella tertiolecta, Tetraselmis suecica, Nannochloropsis oculata, Chaetoceros sp., Chlorellasp. and Spirolina sp. on the growth, survival rate and reproduction efficacy in Artemia urmianain laboratory conditions. Artemia cysts were harvested from Urmia Lake and hatched according to the standard method. Live microalgae were cultured using the f/2 culture medium.Artemia survival was determined in treatments on days 8, 11, 14, 17 and 20. A highly significant difference (p<0.01) were found among three microalgae in terms of length growth, survival rates and reproduction characteristics in A. urmiana. In spite of higher length growth of A.urmiana fed on N. oculata than A. urmianafed by T. suecica but survival and reproduction in the latter was better than the first treatment. In general, D. tertiolecta was more efficient than other microalgae examined in the present study onA. urmiana concerning not only to growth and survival but also to reproduction mode. So, it is preferred to feedA. urmiana.

A study was conducted to appraise the effect of different stocking densities on three male morphotypes named blue claw (BC), orange claw (OC) and small male (SM) at harvest in all-male culture and to assess the growth performance of BC, OC and SM in each isolated culture. Trials involving three stocking densities of all-male prawn viz., 20, 30 and 40 juvenile m-2 were carried out in replicates. After 4 months of culture, BC, OC and SM were sorted from all tanks and restocked at 5 m-2 in treatments BC, OC and SM respectively for 80 days. A difference in prawn density significantly (p<0.05) affected adversely on morphotypes. The highest survival rate combined with good yield performance was from 20 juvenile m-2 stocking density with 21% BC, 62.5% OC and 16.5% SM, respectively. In isolation culture, the average specific growth rate of the SM population (1.22) was significantly higher than that of the OC (1.01) and the BC (0.43) population. The survival of the SM population was 100% while for others it was 72%.Absolute weight of prawn was significantly greater in the male OC (23.87 g) than the SM (19.57 g) and the BC males (6.31 g). Impacts of isolated culture on population structure were much more pronounced in the SM population than others.

The effects of n-3 highly unsaturated fatty acids (n-3 HUFA) were studied on Beluga (Huso huso) fish larvae by feeding fish larvae with live food enriched with 4 different oils (ICES 30.4, tuna eye oil, flaxseed oil and cottonseed oil) containing different levels of n-3 HUFA including 27.19, 20.33, 12.71 and 0.39 mg g-1 dry weight of oil, respectively. Fish larvae weighing 30.00±2.00 mg were randomly divided into 12 groups of 150 fish each and triplicates fed the 4 experimental diets for 3 weeks. There were no differences in survival rates, but significant differences were found in growth rates and fatty acid composition of the fish larvae after 30 days. Fish fed low levels of dietary n-3 HUFA (0.39 mg g-1 DW) showed poor n-3 HUFA contents but these fatty acids improved with the elevation of the n-3 HUFA levels in the diet up to 20 mg g-1 DW. Fish fed the flaxseed oil showed the highest level of crude lipid 15.00±3.01).Results showed that tuna eye oil and ICES30/4-enriched live food (4.83 ±1.29 and 4.61±0.99 mg g-1 DW, respectively) showed the highest n-3 HUFA content for sturgeon fish larvae.

Aeromonasinfections are the most common bacterial disease of cultured fish in China.In this study, a gram-negative bacillus was isolated from the liver of diseased koi carp (Cyprinus carpio koi), and named strain KC-2. The results of morphological and biochemical tests, as well as phylogenetic analysis derived from16S rRNA and gyrB sequences indicated that the isolated strain KC-2 was highly identical to the known Aeromonas mediaATCC 33907. Experimental infection assays were conducted, and pathogenicity was demonstrated in crucian carp (Carassius auratus) and zebrafish (Danio rerio). Antimicrobial susceptibility testing showed that the strain KC-2 was sensitive to cefalotin, cefixime, cefotaxime, gentamicin, netilmicin, azithromycin and chloramphenicol. This is the first report on the isolation and identification ofA. media from diseased, cultured koi fish. The results of the study will provide a scientific reference for prevention of bacterial disease of koi carp and identification ofA. media in fish.

The present study aimed to elucidate the impacts of dietary vegetable oil blends as alternative to fish oil on serum biochemical and haematological parameters in Heterobranchus longifilisfingerlings. Fish (4.65 ± 0.23g) were fed diets containing fish oil (FO), palm oil (PO), soybean oil (SO), blend of PO and SO (POSO) over a 12-week period. The experiment was carried out in 62-l circular tanks with 10 fish per tank. Fish were fed two times a day until apparent satiation. At the end of the experiment, blood samples were collected from each treatment for investigation of serum biochemical and haematological parameters. The results showed that total protein was not significantly affected by the different dietary lipid sources (p>0.05). However, serum glucose was significantly higher in fish fed the control diet (p<0.05). Activities of liver enzymes (AST, ALT, ALP), total cholesterol, triglyceride, LDL and HDL exhibited a significant increase in the blood of fish fed combinations of the vegetable lipid sources (p<0.05).The PCV, RBC and MCV were not affected by the dietary lipid sources (p>0.05).These results indicate that FO can be replaced with PO, SO or their combinations in the diet ofH. longifilis fingerlings without any negative health impacts.

This study was done to evaluate the antimicrobial and antioxidant effects of nisin Z (0.02 %) and sodium benzoate (1.5 and 2.5 %) in vacuum packed Caspian Kutum (Rutilus frisii) fillet stored at 4°C. Microbial changes [aerobic plate counts (APC), psychrotrophic counts (PTC) and lactic acid bacteria] and chemical indices [peroxide value and total volatile basic nitrogen (TVB-N)] were determined in days 0, 4, 8, 12 and 16. Results showed that PV and TVB-N in control samples (the sample dipped in prechilled distilled water) were deteriorated after 12 days compared to preserved samples which were acceptable after 16 days. Microbial tests indicated that control samples contained APC and PTC bacteria in day 16 more than standard limit, whereas treatment samples were in the acceptable range. In case of lactic acid bacteria, after 16 days, all samples were in the acceptable range. Results of chemical and microbial analysis showed that simultaneous use of nisin Z and sodium benzoate could increase the shelf life of vacuum packedR. frisii.

The antioxidant activities ofUlva faciata, Nizimuddinia zanardinii and Gracilaria corticatawere investigated in Chabahar, Iran. Methanol extract and n-hexane, dichloromethane and ethylacetate fractions used for antioxidative properties test by the total antioxidative activity, 2, 2-diphenyl-1-picryl-hydrazylhydrate (DPPH) free radical scavenging activity, reduction power, metal chelating activity and inhibition of lipid peroxidation methods. The methanolic extracts of three seaweed species showed lower antioxidative properties. The most effective antioxidant properties were observed from the EA fractions ofG. corticata and U. faciata. dichloromethane (DCM), fraction of N.zanardiniishowed significantly higher total antioxidative activity, DPPH radical scavenging and power reduction in comparison to its n-hexane, EA fractions and crude MeOH extract. There was a strong correlation between the reduction power (r2=0.94) and the total phenolic content of the seaweeds extracts and fractions. The results indicateU. faciata and G. corticata can be potential sources of natural antioxidants and may be efficiently used as nutraceuticals.

Fatty acids composition in edible parts of Blue Swimming Crab (Portunus pelagicus) caught in the Persian Gulf close to the Bushehr Province were investigated. Among saturated fatty acids (SFA), the 16: 0 and 18: 0 fatty acids were the most two dominant fatty acids in meat tissues that analyzed.18: 1n-9 and 16: 1n-7 were the major fatty acids among the MUFAs of male and female crab. The main PUFAs in lipids of crab meat were 20: 5n-3 and 22: 6n-3. The n-3 PUFA content was highest in female claw meat (20.26%) and lowest in male meat (11.31%), respectively. The sex and tissue had a significant influence on the EPA, DHA and n-3 HUFA. The highest amounts of DHA and the favorable n-6/n-3 ratio in the meat of blue swimming crab indicate that the claw and breast meat is a very omega-rich edible portion of crab body.

This study was carried out to determine population structure, growth and reproduction properties of barbel. A total of 198 individuals were sampled. Ages of samples were found between I and VI years, fork lengths between 4.3 and 16.6 cm and total weights between 1.2 and 65.8 g. Length-weight relationship was calculated as W=0.0146×L2.934.Munro’s phi prime index was estimated as 1.95, L¥ as 26.42 cm W¥ as 216.92 g, and condition factor as 1.265±0.01. First sexual maturation was determined in 6.0-6.9 cmgroup males, and second sexual maturity was recorded in 10.0-10.9 cm-group females.Individual fecundity was defined between 568 and 4171 eggs/female and relative fecundity was calculated as 64964.55±5855.49 eggs/kg female. Barbel did not show good growth and reproduction performance in the stream, because of fishing pressure.

Streptococcosis has been defined as a hemorrhagic septicemia in many fish species especially rainbow trout. This disease causes serious economic losses due to high mortality in fish and the bacteria responsible is also considered as a zoonotic pathogen. The aim of this study was identification of different causative agents of warm water streptococcosis and evaluation of the capsule gene in Lactococcus garvieae isolates collected from rainbow trout in Chaharmahal - Bakhtiari Province, Iran. A total of 430 clinically suspected fish were collected from 43 rainbow trout farms. The samples were analyzed using biochemical methods and multiplex-PCR. The results indicated that samples of 36 fish farms (83.7%) were infected with one of the studied bacteria. The infection by L. garvieae was found to be more than that by other species (30 of 36 farms, 83%). Infection by S. iniae and S. uberis was found in nine and one fish farm, respectively. Presence of virulence genes was studied in L. garvieae isolates by PCR assay. According to the results 34 of 50 isolates (68%) contained the capsule gene. The results revealed high prevalence of virulent L. garvieae in rainbow trout farms which should be considered in preventional policies such as vaccine production and also in public health.

The present study was conducted based on the fish species and physicochemical parameters of Egirdir Lake. Sampling was carried out monthly from January through December 2010 between 9 am and 11 am. The parameters measured were water temperature, depth, secchi disk depth, turbidity, dissolved oxygen, saturation of dissolved oxygen, pH, conductivity, chloride, hardness, calcium, magnesium, bicarbonate, carbonate, nitrate, nitrite, ammonium, sulphate, phosphate, silica, organic substance, acid power (SBV) and chlorophyll-a. Monthly sampling was performed at four stations at different depths. Water temperature ranged from 6.9±0.5oC in February to 26.8±0.4oC in August. Minimum secchi disk depth recorded was 0.5 m while the maximum was 2.4 m. Dissolved oxygen ranged from 4.2±0.2 to 12.6±0.6 mgL-1. The pH values ranged from 8.4 to 9.6. In this study, 15 fish species, belonging to eight families were identified. Among the 15 fish species recorded, Cyprinidae was the dominant family followed by Percidae (3 %). According to detrended correspondence analysis (DCA), variables were able to explain 90 % of total variation suggesting a significant result. The results showed that water temperature, dissolved oxygen and saturation of dissolved oxygen were the most important physicochemical parameters affecting fish distribution. Other pyhsicochemical parameters of this lake did not show any significant statistical differences in determining fish distribution.

The present research aimed to determine acute toxicity and evaluate the effect of sub-lethal concentrations of diazinon on some haematological and immunological parameters ofBarbus sharpeyiby the Organization for Economic Cooperation and Development methods. Juvenile B. sharpeyiwere exposed to 0, 5%, 10% and 25% 96h LC50 concentrations of diazinon for 21 days. Blood samples were taken after 7, 14 and 21 days of exposure to diazinon.Haematological and biochemical parameters including: RBC, Hb, PCV and WBC, as well as serum enzymes were evaluated. Immunological indices and resistance against bacterial infection, were determined. Results showed that 96h LC50 of diazinon inB. sharpeyi was estimated at 3.987 mg/L. Diazinon toxicity at a level of 1 and 0.4 mg/L decreased RBC, Hb, and Hematocrite, in almost all sampling periods compared. WBC and globular index decreased significantly in fish exposed to 1 mg/L diazinon on days 14 and 21 (p<0.05). Dose dependent increase in serum enzymes were seen in fish exposed to diazinon. Diazinon toxicity showed no effect on serum LDH level (p>0.05). Dose dependent decrease in serum total protein and globulin were indicated in diazinon exposed fish. Serum lysozyme and bactericidal activity decreased in T3 and T4 at days 14 and 21. Mortality following challenge toA.hydrophila increased in fish exposed to 1 mg/l diazinon. It can be concluded that diazinon is toxic toB.sharpeyi. Therefore, the strict biosecurity should be taken into consideration when this pesticide is used in agricultural fields surrounding freshwater sources of fish cultivation.

A 60-days growth trial was conducted in a flow-through culture system to examine the effects of different dietary vitamin C and iron levels on the growth, hematological and immunological parameters of rainbow trout (Oncorhynchus mykiss) fingerlings (with average initial weight of 5.12 ± 0.02 g). Three levels of vitamin C (150, 200 and 250 mg kg-1 diet) and iron (5, 7 and 9 mg kg-1 diet) (as ferrous sulfate) and their combination were used to prepare diets used in nine experimental treatments with three replicates. The results revealed that the supplementation of basal diet with vitamin C and iron significantly affected the final body weight (FBW), total length (TL), feed conversion ratio (FCR) and specific growth rate (SGR). Among the haematological parameters haematocrit and mean corpuscular volume (MCV) were significantly influenced by vitamin C and iron. Results also showed that lysozyme and IgM concentrations significantly changed among dietary treatments. Based on the results of this study, it can be conclude that addition of vitamin C and iron to the basal diet of cultured rainbow trout will improve the growth rate and well-being of this fish.

The bioavailability of methylmercury (MeHg) in the brains of orange spotted groupers, captured from four creeks of Mahshahr embayment was measured. Then the effects of this pollutant on the regulation of gene expression, acetylcholinesterase transcript levels was chosen in order to monitor the amounts of methylmercury concentrations in the creeks, and the fluctuations of mRNA expressions in the brain and their effect on fish health. Fishes were collected from Zangi, Ghanam, Marymous and Petrochemical Creeks, and their brains were removed by dissection. In parallel with these experiments some fishes were exposed to methylmerucry chloride in the Fisheries center and the amount of their gene expression was assessed via Real-Time PCR method. The lethal concentration of methylmerucry causing the mortality of half of the fish population after 96 hr (LC50-96) was assessed and gene expression of sub-lethal concentration (more and less than 10% of LC50-96) were analyzed. Gene expression studies revealed that the most polluted creek was the Petrochemical Creek, and the least polluted one was Marymous Creek. This regulation was assessed by the effect of MeHg on the gene expression, meaning the more gene expression, the less polluted and vice versa. From this study we concluded that acetylcholinesterase gene expression can serve as a biomarker of the effect of methylmercury, which can provide a good estimation of the amount of methylmercuric availability in the brain ofEpinephelus coioides and its effect on the brain neurotransmission pathway.

This study was designed to determine the technical and economic efficiency levels of the commercial basal feeds enriched with 10%, 5% and 0% rates of LNA (LNA10, LNA5and LNA0) on the growth performance of brown trout by analyzing the marginal factor cost (MFC) and the marginal revenue of physical product (MRPP). A total of 300 brown trout with an initial individual weight of 4±0.05 g were randomly divided in 12 cages (25 fingerlings in each cage), and kept under 24L: 0D (light/dark) photoperiod condition for 9 weeks treated by LNA10, LNA5 and LNA0. The results of the study showed that LNA0 and LNA10 of the effective feed sources, respectively on the growth performance of brown trout were more suitable to produce as the homogeneous products for the consumers and differentiated those for the drug industry in view of the economic and technical efficiencies.

A total of 98 marine mammal records from Iranian coastal waters of the Persian Gulf and Gulf of Oman were compiled of which 66 are previously unpublished new records. Seventynine were from the Persian Gulf and 16 from the Gulf of Oman coast. The largest numbers of records were from Qeshm Island and Bushehr Provinces. Records of finless porpoise (Neophocaena phocaenoides), Indo-pacific humpback dolphin (Sousa chinensis) and Indopacific bottlenose dolphin (Tursiops aduncus) were by far the most numerous probably reflecting their inshore distribution and local abundance. Other species recorded are common dolphin (Delphinus capensis tropicalis), rough-toothed dolphin (Steno bredanensis), Risso’s dolphin (Grampus griseus), false killer whale (Pseudorca crassidens), and dugong (Dugong dugon).Evidence of 22 Mysticetes were obtained eight of which were tentatively identified as Bryde’s whales (Balaenoptera edeni), three as fin whales (Balaenoptera physalus) and three as Humpback whales (Megaptera novaeangliae). The largest threat to marine mammals in Iran is likely to be incidental capture in fishing gear. Six by caught finless porpoises were recorded and this species may be particularly vulnerable to incidental mortality in gillnets.Recommended marine mammal research, conservation and management small projects in Iran are described.