Iranian Journal of Fisheries Sciences
Volume:19 Issue: 4, Jul 2020

Concentrations of lead, copper, cadmium, and mercury were determined in sediments and two selected marine organisms (Cynoglossus arel and Panulirus homarus) collected from Jask Port, Darak Port, Pozm Port, Gulf of Chabahar and Gowatr Port in the north coasts of the Oman Sea during pre (spring) and post (autumn) monsoon in 2017. Heavy metals concentrations were determined by atomic absorption spectrophotometry. Results showed that there are statistically significant differences between studies concentrations in sediments during pre and post-monsoon at sample locations (p<0.05). Analysis of variance revealed a significant difference in the muscle of C. arel and P. homarus in pre and post-monsoon between the different sites (p<0.05), except for copper in the muscle of P. homarus in the post-monsoon (p>0.05). In sediments and muscle of C. arel and P. homarus the trend in the mean metal concentrations was: Cu> Pb> Cd> Hg; Cu> Pb> Cd> Hg and Cu> Hg=Pb> Cd, respectively. Also, the trend in the mean metal concentrations in the samples was sediment > P. homarus> C. arel. However, paired t-test analysis for comparing heavy metal concentration in pre and post-monsoon showed only a significant difference for cadmium in the muscle of P. homarus (p<0.01). Totally, by comparing the results obtained from this study indicated that the accumulation of lead, copper, cadmium, and mercury in sediments and muscle C. arel and P. homarus at the Gulf of Chabahar and Jask Port is higher than other regions of the Iranian coasts along the Oman Sea which studied in current research.

The mangrove forest ecosystem is known to possess a variety of ecosystem services, including high rates of carbon sequestration, storage and mitigating climate change through reduced deforestation. This study was carried out in the mangrove forests of Gowatr Bay, Gulf of Oman during 2017-18 to quantify biomass and carbon stocks of all components of this forest, including live and dead trees, soil, pneumatophores, herbaceous and litter in three stations during post-monsoon and pre-monsoon. We examined that biomass, carbon stocks and soil carbon varied significantly with spatial locations (p<0.05) abut not with seasons (p>0.05). The mean of biomass and carbon stock were estimated 125.54±19.31 and 129.21±19.64 Mg ha-1, and 48.48±7.51 and 49.9±7.5 Mg ha-1, in post-monsoon and pre-monsoon, respectively. Also, Soil carbon was determined 227.1±11.86 and 227.3±11.71 Mg ha-1 in post-monsoon and pre-monsoon, respectively. A positive correlation was found between the vegetation biomass and soil organic carbon in post-monsoon (r=0.905) and pre-monsoon (r=0.914), indicating the role of vegetation in building soil organic carbon. The mean carbon stock value for the total area of mangroves in post-monsoon and pre-monsoon was extrapolated as 43.9 and 44.2 Kt of C, equivalent to 161.13 and 162.102 Kt of CO2, respectively. This data reveals that Gowatr mangroves store a substantial amount of atmospheric carbon, and therefore need to be conserved and sustainably managed to maintain as well as to increase carbon storage.

In this study, 50 000 European seabass and 50 000 gilthead seabream with an average wet weight of 1.6 g were cultivated during 600 days under low water salinity conditions (7‰) of which getting out from underground at fixed 19°C, being produced in earthen ponds under commercial production conditions. From the beginning to the end of the experiment, the same fish feeds were used for both species throughout the study, and when European seabass reached 328.4±22.98 g, gilthead seabream reached to 369.12±24.11 g. At the end of the experiment, while the feed conversion rate (FCR) was calculated as 1.72±0.06 for European sea bass, it was calculated 1.53±0.03 for gilthead sea bream. Protein efficiency ratios were 1.24±0.17 for European seabass, and 1.40±0.06 for gilthead seabream. Significant differences were found between two species in terms of live weight and FCR (p<0.05), while no difference was found related to the specific growth rate (p>0.05). The results showed that gilthead seabream taken into earthen ponds and low salinity brackish water was able to reach 300 g and over live weight with faster and lower FCR values compared to European sea bass in the certain time.

This research investigated the feasibility of using three strains Lactobacillus sp. viz. AM11, AM13, and AM14 previously isolated from dairy products to be used as probiotics in fish diet for phytase production. The bacteria grown in oxygenated media, bile salt, acid and supernatant of digestive tract  were examined for their antibiotic resistance and non-pathogenicity for using in fish feed. Results indicated that the isolates might be attractive candidates as probiotic strains in rainbow trout. All strains were capable of growth and produced phytase in a pH range from 3.0 to 8.0. The isolated strains were also resistant in bile salts and supernatant of digestive tract. No mortality has been observed in the fish injected by bacterial strains. No bacterial growth has observed in the liver, kidney and spleen media after 24 h. Therefore, the examined Lactobacillus strains were non-pathogenic. Due to the low resistance of these strains to tetracycline (antibiotic), it is suggested to avoid using tetracycline in rainbow trout farms when the bacterial strains are used as probiotic. According to the results, the three isolated resistant strains can be employed as probiotics in fish feed.

A feeding trial has been conducted to evaluate the effects of dietary nucleotide (NT) on growth performance and stress resistance of fry kutum (Rutilus kutum Kamenskii, 1901). A basal diet supplemented with 0 (control), 0.3, 0.5 and 0.7 g NT kg-1 have been formulated for four experimental diets. After 8 weeks of feeding trial, growth parameters were evaluated and then fish has exposed to osmotic stress. To elucidate the underlying physiological mechanisms, cortisol, apoptosis and HSP70 levels were measured at selected times of 0, 2 h, 8 h and 24 h after the osmotic shock. The results revealed dietary NT feed exerts a positive effect on the growth performance of kutum fries and fish fed with 0.7 g  NT kg-1 had the highest final weight compared with other treatments (p<0.05). Results of HSP70 showed that fish fed with NT had higher levels of HSP70 expression. Also, the levels of HSP70 at 2 h increased significantly, 3-7-fold over baseline levels (0 h) and then decreased significantly at 24 h, however HSP70 levels at 24 h was 1-3-fold over baseline levels. Apoptosis and cortisol values were affected by dietary NT levels and all NT groups showed lower stress-induced apoptosis and cortisol elevation, compared to control group.

The economic growth of aquaculture and the dependence of a large growing population on coastal resources have led to coastal degradation and reduced resources. In this paper while realizing the potential capacities of the island systems,  the aquaculture activities of the island are specially discussed  in the framework of Integrated Coastal Zone Management (ICZM). Therefore, in this study, firstly, the internal strategic factors (strengths and weaknesses) and external factors (opportunities and threats) of the environment were identified. Thereafter, Analytic Network Process (ANP) and Super Decision Software in SWOT matrix were used to evaluate and prioritize these factors, as well as to develop several proposed strategies. Using a designed network model, the proposed strategies were weighted and the main strategies of the evaluation matrix were ranked. In this study, the Qeshm Island as the largest island in the Persian Gulf was identified as the study area. The results showed that the most efficient strategies to optimal development of aquaculture use of coastal areas of Qeshm Island are using objectives, policies, and plans of aquaculture and aquatic hunting to build and strengthen sustainable aquaculture in the region, build and strengthen comprehensive aquaculture plans for conservation of natural marine resources in the framework of ICZM, create and develop infrastructure facilities and aquaculture infrastructure in order to create optimum use of the lands, allocate adequate funding to achieve conservation programs and user development of aquaculture and environmental protection involved in (ST) strategies.

The present study investigates the effects of varying levels of dietary fermented Aspergillus oryzae (0 g Kg-1 as control group, 10, 20 and 30 g Kg-1) on performance and haemato-immunological indices of common carp (Cyprinus carpio) fingerlings. Common carp fingerlings (n=240, w=4.56±0.17 g) were supplied, randomly stocked in 12 aquaria and fed with experimental diets for 7 weeks. The results revealed no significant differences between performance parameters of fermented A. oryzae fed test and control diets (p˃0.05). Also, evaluation of haematological parameters (RBC, Hct, Hb) and white blood cell (WBC) counts showed no notable changes between experimental groups (p˃0.05). However, respiratory burst activity was meaningfully higher in fish fed fermented A. oryzae compared to control group (p<0.05). The present results showed that possible effects of administration of fermented A. oryzae on immune responses in carp fingerlings.

The aim of this research was to evaluate the changes of some biochemical parameters in response to environmental variation in two important fish species which have great commercial value reared in Sicily. The study, carried out on 200 fish (100 Sparus aurata Linnaeus, 1758 and 100 Dicentrarchus labrax Linnaeus, 1758), lasted 12 months. Each season, blood samples having been collected during summer solstice, autumn equinox, winter solstice and spring equinox. For each time point, 25 S. aurata and 25 D. labrax have been used and always randomly captured by the same batches from tanks. One-way analysis of variance (ANOVA), followed Bonferroni’s multiple comparisons test, has used to evaluate the influence of different seasons on serum protein profile, aspartate aminotransferase (AST), alanine aminotransferase (ALT), urea, calcium, magnesium, triglycerides and total cholesterol. The results showed the seasonal influence on biometric and biochemical parameters studied in S. aurata and D. labrax and that seasonal cycles can differently affects fish in several biological and physiological activities. These results could represent a valid contribution in the study of the linkage between metabolic parameters, seasonal variations and biometric indices in cultured fish to improve the management and technological support of aquaculture.

Procambarus clarkii crayfish has been developed as an excellent animal model to study the characteristics and pathogenesis of white spot syndrome virus and the host defense mechanisms of crustacean. However, due to pathogen infections of crayfish in Chinese farms, research based on this model has been slowed down. Using triplex polymerase chain reaction, we found the virulence Aeromonas hydrophila was one reason that caused the death of crayfish. The isolated AH-3 produced 100% mortalities with 3-24h after inoculation of 1×106 colony-forming units of live cells per crayfish at 20 ˚C.

Fungal assist microalgal cultivation is getting substantial considerations due to the highly efficiency of bioflocculation process without demanded of using chemicals and little bit energy input. Therefore, Fungi pelletization-assisted microalgal cultivation were applied for improving algal harvesting process and nutrient recovery as step wise for wastewater treatment. Two strains of marine microalgae (Nannochloropsis salina and Chlorella salina) and three species of marine fungi (Penicillium chrysogenum, Aspergillus niger and Aspergillus fumigatus) were implied to investigate the effect of fungi-algae pelletization process on wastewater recovery. After 48 hour of cultivation, the highest flocculation efficiency (98.9%) was recorded by A. fumigatus assist C. salina, while the lowest percentage (85.9%) recorded by A. niger assist N. Salina. The highest nutrient removal percentage was for nitrite by A. niger assist C. salina /tap water (98.4%) followed by phosphate A. fumigates assist N. salina/sea and tap water (90.9%), then ammonia by A. fumigates assist N. salina/seawater (89.5%). The bioflocculation process is a promising for algal harvesting techniques and wastewater nutrient recovery.

Since chemotherapeutic agents used to control microbial fish diseases have led to resistance in bacteria, alternative methods have emerged in recent years. In this regard, identification of lactic acid bacteria with good probiotic properties and determination of their probiotic properties are extremely important. In this study, 25 lactic acid bacteria were isolated from freshwater fish and identified at species level using phenotypic, biochemical and molecular tests. The pH tolerance, antagonistic activity and antibiotic sensitivity of these 25 strains were examined, and they were considered as bacteria displaying the best activity in the potential probiotic treatment of fish diseases. Lactococcus lactis species numbered F2, F4, F9 and F10 were determined to have a potential probiotic capacity.

Many scientists have been studied on water quality and solid removal from Recirculating Aquaculture Systems (RAS), but the solid removal problem did not solve completely yet. This paper is based on experimental data on a cylindrical tank in diameter of 0.53 m and height of 0.17 m and inlet flow using six nozzles in 2 mm diameter to determine solid removal efficiency by comparison with some different scenarios. The results indicate that using submerged vanes on the bed of the tank may improve removal of solid particles. In this paper 10 different scenarios compared and some of them showed more effectiveness on solid removal. The number of submerged vanes in outer pyramid of the tank bed does not necessarily reduce amount of sediment discharge efficiency, and the location of each vane makes a special impact on the context of hydraulic conditions and solid removal as well. The experimental observations showed, the second scenario (12 submerged vanes in binary groups) and the third scenario (7 submerged vanes in 45º by the vicinity of the tank wall) have significant impacts on sediment discharge efficiency.

This study evaluated the effects of diets containing various carbohydrate-to-lipid (CHO L-1) ratios on growth performance, nutrient utilization body indices and hepatic lipogenic enzyme (malic enzyme, 6-phosphogluconate dehydrogenase and fatty acid synthase) activities. Triplicate groups of Pangasianodon hypophthalmus fingerlings were fed eight isoenergetic and isonitrogenous diets with different carbohydrate-to-lipid ratios (0.51, 0.79, 1.12, 1.79, 2.41, 3.24, 4.43 and 7.62). Higher body fat deposition and lower growth performance were observed in P. hypophthalmus fingerlings fed with high-lipid diet than those fed with high-carbohydrate diet. The fish fed the diet with 7.62 CHO L-1 ratio exhibited significantly (p<0.05) higher hepatosomatic index compared to those fed higher lipid diets (0.51 and 0.79). High dietary carbohydrate level significantly increased (p<0.05) the activities of malic, 6-phosphogluconate dehydrogenase and fatty acid synthase enzyme. Based on the second-order polynomial regression analysis of weight gain, the optimal dietary carbohydrate and lipid contents for P. hypophthalmus fingerling were 304 and 103 g kg−1, respectively, which correspond to a dietary CHO L-1 ratio of 2.95.

A feeding trial was conducted to evaluate the effects of dietary crude protein and energy levels on the live weight (LW), daily weight gain (DWG), feed conversion rate (FCR), feed efficiency (FE), protein efficiency rate (PER), survival rate (SR), specific growth rate (SGR), thermal growth coefficient (TGC) and carcass composition of catfish (Clarias gariepinus). In this trial a group of 80 catfish were randomly assigned per tank in 3 replicates and fed different levels combination of crude protein and energy, viz: three levels of crude protein (CP) (32; 34; and 36%) with digestible protein (DP) (27; 39; and 41%) and three levels of digestible energy (DE) (11.9; 12.4; and 13.3%) for 8 weeks. At the end of experiment, the results showed that the highest LW, DWG, SGR and TGC were found in fish fed 34% CP: 39% DP: 12.4% DE. The better FCR was reached in fish fed 36% CP: 41%DP: 12.4% DE whereas highest PER was in fish fed 34% CP: 39% DP: 13.3% DE. Meanwhile, fish fed 36%CP: 41% DP: 12.4% DE resulted in significantly higher FE. However, the SR of fish was not affected by any combination of CP: DP: DE. This finding indicated that 34% CP: 39% DP: 12.4% DE was the optimum combination in enhancing the growth of catfish.

Growth and survival rate in the larval stages of marine fish are influenced by the live feeds. Different methods were used for enrichment of the live feeds with vitamins and fatty acids, however, those methods cannot be used for soluble materials such as zinc. So, in this research, the effects of zinc-threonine enriched Saccharomyces cerevisiae, on growth factors and mineral composition of marine rotifer, Brachionus plicatilis was investigated. For this purpose, rotifers in four groups including: 1) yeast without enrichment (the control), 2) yeast containing 18.22 mg g-1 of zinc 3) yeast containing 23.76 mg g-1 of zinc and 4) yeast containing 46.15 mg g-1 of zinc were cultured for 10 days. Based on results, in group with 46.15 mg g-1 of zinc-threonine the specific growth rate (SGR) and mineral composition of rotifers significantly improved (p<0.05). Maximum number of rotifers and eggs were 219.3±2.0 and 30.3±11.0 number ml-1, respectively. The eggs ratio (the number of eggs/total number of female rotifers) and SGR is related to the group of 23.76 mg g-1 and 46.15 mg g-1 of zinc-threonine, respectively. Highest amount of zinc in treatment 4 was 977± 4.99 mg kg-1 of rotifers. Also the amount of Cu in treatment 4 was significantly higher than other groups. Conversely, by increasing zinc content, other ions levels like Fe and Mn were significantly decreased (p<0.05). In conclusion, zinc-threonine enriched yeast could improve the growth, reproduction and mineral composition of marine rotifers, Brachionus plicatilis.

Organizational entrepreneurship is a process during which organizations recognize growth and development opportunities and create new values for customers through innovation and resource re-allocation. Besides, a variety of factors affect organizations' entrepreneurship capacity. In fact, the present paper aims to identify and rank effective factors on organizational entrepreneurship in Mazandaran Province's Fisheries Organization through applied, descriptive–survey methodology. Research population is composed of management and entrepreneurship experts and professionals of Mazandaran Fisheries Organization. This paper, first, reviews related literature. Then, effective factors on entrepreneurship are identified and classified into three groups (behavioral, structural, environmental factors). Required data is collected through Delphi's questionnaire and pair comparisons and are analyzed using Fuzzy Delphi Method (FDM) and Fuzzy Analytical Hierarchy Process (FAHP). Results indicate that effective factors on entrepreneurship are prioritized as: behavioral factors, structural factors and environmental factors. It is clear that organizational entrepreneurship is an important concept advantages of which have emerged more significantly, during recent years, to many organizations, firms and business agencies in various subsections such as industry, agriculture and Fishery and this provides organizations with a variety of social and economic benefits.

The efficacy of neem (Azadiracta indica) against Lernaea cyprinacea was studied. Two types of neem seeds powder, viz; (1) dried and powdered neem seeds and (2) solvent extracted neem seeds powder prepared by treating dried seeds powder with petroleum ether were used in the present study. These experiments were carried out in the month of August 2014. Different types of extracts were prepared by separately solubilising both types of neem` seeds powder in i) 1% NaCl solution and (ii) water at two temperatures (28 oC and 90oC). These extracts were tested at varying concentrations (10, 25, 50 and 100 µg mL-1) against Lernaea. Results indicated that neem seeds powder treated with solvent and further solubilized with hot water (90 oC) at a concentration of 100 µg mL-1 was effective in preventing the hatching of L.cyprinacea eggs and their further development. Nauplii and copepodid-I stages were also exposed to above mentioned neem seed extracts at a concentration of 100µg mL-1. Nauplii became inactive within 2 hrs and copepodids died after 43 minutes exposure to solvent treated neem`s powder extracted with hot water. Fishes (Labeo fimbriatus) survived for an average period of 5 and 30 min in all types of neem seeds extracts except the one extracted with water at 28oC (both solvent treated and untreated neem`s seeds powder).

This is the first study with the greatest number of multimetric indices calculated in Iran to assess water quality at Jajrood and Karaj protected rivers. Given the point that these rivers supply  a large portion of Tehran's drinking water, the present study aims at determining ecological quality of these rivers based on a suitable biotic index among these indices. Physicochemical and macro-invertebrate samples were collected with three replications during three consecutive years from 19 stations with a Surber sampler. In the Jajrood River, macroinvertebrates with 6667 abundance belong to 22 families and in the Karaj River, macro-invertebrates with 13,246 abundance belong to 24 families have been identified. The most appropriate time for sampling is in summer because of the existence maximum abundance and diversity of macroinvertebrates. The results of CCA have been shown physicochemical parameters TSS, EC, pH, and BOD have the most effect on the distribution of macroinvertebrates. Among the 16 biotic indices, the FBI index in Karaj River and the BMWP/ASPT index in the Jajrood River are the most reliable indices for assessing the water quality. The results showed that point pollution sources (orchards, restaurants and villages) and nonpoint sources (tourism activities and recreational area) have the most negative impact on the ecosystem of these two rivers. Results of water quality assessment have been shown the changes in ecological quality of water due to human activities; therefore, it is necessary to increase control and management of pollutant sources to improve the water quality of these two rivers.

The use of plant proteins in substituting fishmeal (FM) is mitigated by several anti nutritional factors (ANF) like phytic acid, non starch polysaccharides and protease inhibitors. Fermentation of the plant ingredients can reduce the ANF and improve feed utilization and growth rate of fish. We produced five isonitrogenous and isocaloric diets using solid state fermented  bambara nut  meal (BNM). Fermented BNM substituted FM in diets of African catfish Clarias gariepinus. The FM: BNM inclusion percentages of the diets were, F1, 50:5; F2, 35:20; F3, 20:35; F4, 5:50 and F5, 0:56. There was a control feed labelled as F6. Feed F6 was a variant of F1 but with non fermented BNM. Fingerling African catfish C. gariepinus with average weight 5.14±0.05 g were fed with the diets for 56 days. Specific growth rate (SGR) was best for the catfish fed with F1, 7.82±0.25 % day-1, followed by those fed with F6, 7.35±0.24 % day-1. There were, however, no differences in SGR of F2, 7.26±0.18 % day-1 and F6. The food conversion ratio was lowest and best for the catfish fed with F1, 1.24±0.19 and F2 1.34±0.06. The growth and nutritional performance of fish fed with F2 were as good as F1 and cost-effective. Feeds made from fermented BNM had better FCR than those from raw BNM. Fermentation increased the protein and amino acid content of the BNM and the catfish gained more weight than from raw BNM. The effects of ANF seem to be highly reduced in solid-state fermented BNM thereby enhancing catfish growth.

In this study, the antibacterial and antioxidant properties of C-phycocyanin (C-PC) from Spirulina platensis were evaluated. The extraction and purification of C-PC were carried out using lyzosyme and ammonium sulphate precipitation, respectively. DPPH radical-scavenging activity, ferric reducing antioxidant power (FRAP) and Fe2+-chelating activity were used for evaluation of antioxidant properties of C-PC. Antibacterial activity was also performed using agar well diffusion and microdilution [minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC)]. The selected bacteria were Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Streptococcus iniae and Yersinia ruckeri. The results showed that the biomass production was 1120 mg L-1 and C-PC concentration in crude extracts and purified by (NH4)2SO4 were also 1.815 and 3.75 mg ml-1, respectively. The results of DPPH, FRAP and Fe2+-chelating activities of C-PC was 45.75%, 0.051 mg TAE g-1 and 40.23% at zero time and 41.56%, 0.046 mg TAE g-1 and 36.56% after 60 days at -18°C, respectively. The results of agar well diffusion indicated that L. monocytogenes and S. iniae were the most sensitive and resistant, respectively among examined bacteria in different concentrations of C-PC (0- 25 µg ml-1) and the mean of inhibition zones were also 7.50-22.11mm. The results of MIC and MBC of C-PC (as µg ml-1) were 50-500 and 100-500, respectively. As a conclusion, C-PC from S. platensis had high potential of antioxidant activity in vitro and it can be used as natural antioxidants in variety of foods. Antibacterial activity of C-PC was lower than other algal pigments (such as astaxanthin and C-PC in other cyanobacteria).

Broodstock maturation diets are an important component of shrimp hatchery management, since the nutritional status of spawners can impact on gonadal maturation, egg fecundity, embryo hatchability and overall larval quality. The ability to manipulate the biochemical composition of Artemia to deliver key nutrients to cultured animals has rendered their inclusion in broodstock feeds increasingly common. Lipid enrichment of Artemia franciscana to boost their unsaturated fatty acid content is a standard procedure.  During this study, frozen, lipid-enriched adult Artemia biomass, squid and mollusc were fed to Litopenaeus vannamei broodstock to investigate the suitability of enriched Artemia as a maturation diet for the species and elucidate the role of essential fatty acids in the reproductive performance of the shrimp. Four lipid enrichment levels: PUFA (P group), MUFA (M group), HUFA (H1and H2 groups), un-enriched (NE group), No-Artemia (NA group), were fed to L. vannamei over 45 days. Significant differences in weight gain and specific growth rate were observed. Greatest mean SGR was recorded for shrimp of P-group as well as greatest mean final weight on day 45, while the lowest mean SGR was found for shrimp fed Diet NA. The fecundity of the broodstock shrimp fed diets either H1 or H2 increased compared with that of the shrimps fed NA (p<0.05). Significant differences in the hatching rate were observed. Changes in gonado-somatic index (GSI) of broodstock during ovarian maturation  were very pronounced, but changes in hepato-somatic index (HSI) were not significantly different between the broodstock groups.

A brood ship sturgeon with the weight of 10 kg, produced 3.6 kg eggs. After the fertilization process, 300 g of eggs (approximately 8800±120 eggs) were distributed into each box of Youchtchenko incubator (each incubator has 4 boxes). The research was carried out with 4 treatments and 3 replications in each treatment. The research was conducted at the International Sturgeon Research Institute and Beheshti Sturgeon Restoration and Genetic Conservation Center, in 2017. Treatments included control (no added trifluralin herbicide) and 3 different concentrations of trifluralin, treatment 1 (0.1 mg L-1), treatment 2 (0.05 mg L-1), treatment 3 (0.025 mg L-1). Trifluralin was added 24 hours after placing the fertilized eggs in the incubator. 48 hours after incubation, the number of fungal eggs reached the highest level in treatments. However, in the control treatment it was significantly more than other treatments) p<0.05(. In treatments 2 and 3 the remaining eggs and the hatching rate, were significantly lower than other treatments) p<0.05(. Possibly, the use of trifluralin in two concentrations of 0.025 and 0.05 mg L-1 had negative effects, which may be due to low concentrations and use as a temporary bath. After 96 hours, the eggs were completely hatched. Hatching rate in treatment 1, was significantly more than control and treatments 2 and 3 (p<0.05). The results indicated that trifluralin can be successfully used in the proper function of Youchtchenko incubator, at a concentration of 0.1 mg L-1.

Persian sturgeon (Acipenser persicus) is one of the most valuable species of fish native in the Caspian Sea and Iran's waters. In order to evaluate the heritability of reproductive traits in wild Persian sturgeon (A. persicus) three males and three  females’ fish were caught in the southern area of Caspian Sea and then were crossed by using a 3×3 factorial with the aim of selecting the best parent to produce good larvae. Prior to the crossing, sperm density, motility, pH and osmolality, spermatocrit percentages, and the number of micropyles on the eggs` surface were determined. One hundred grams of eggs from each females were fertilized by 1mL of sperm from each males for a total of and 9 treatments combinations, (F1M1, F1M2, F1M3, F2M1, F2M2, F2M3, F3M1, F3M2 and F3M3) with 3 replicates each. Hatching percent was calculated at 5 h after fertilization and 405 eggs were measured for weighting and determining their diameter. Sperm concentration and number of micropyles had no significant effects on fertilization rate (p>0.05). Sperm density also had negative correlations with fertilization (r=-0.603, p<0.01) and hatching rates (r =-0.175, p<0.01). However, fertilization was positively correlated with osmolality (r=0.511) and number of micropyles (r = 0.574). The correlation between osmolality and hatching rate was 0.288 and between eggs weight and its diameter was 0.698. Heritability estimates for weight and diameter of eggs were 0.043±0.035 and 0.207±0.103, respectively. The results show treatment 9 (F3M3) had higher genetic values compared to the rest of the treatments. Also due to the large number of micropyle on sturgeon ova, in order to increase the percentage of fertilization rate, sperm density should be low but motility duration should be high.

The bio-sorption of ammonium ions using red marine macroalga Gracilaria persica were investigated by response surface methodology. The sorbent was characterized by SEM and FTIR analysis. The influence of various operating parameters such as ammonium concentration (mg L-1), initial solution pH and alga biomass dosage (g L-1) was optimized using Box–Behnken design. A second-order polynomial model successfully described the effects of independent variables on the ammonium ions removal. At the optimum conditions, the maximum removal efficiency was achieved at 100.01 %. The kinetic results also demonstrated that the bio-sorption of ammonium ions by the dried microalga followed well pseudo-second-order kinetics. FTIR results showed that amide, aliphatic and carbonyl groups might be responsible for the adsorption of ammonium ions in aqueous solution by dried G. persica biomass.

The potential application of settling ponds and two fouling filter-feeder species Amphibalanus amphitrite and Saccostrea cucullata to bioremediate semi-intensive shrimp farm effluent through 6 hours residence time was investigated. Settling pond reduced total nitrogen, total phosphorus and chlorophyll a to 80.5%, 77.8% and 94.3% of the initial concentrations (2.47 ± 0.07 mg L-1, 0.154 ± 0.006 mg L-1, and 24.44 ± 2.02 µg L-1), respectively. Amongst S. cucullata, A. amphitrite and combination of both species, oysters showed the highest efficiency in nutrient removal. Total nitrogen, total phosphorus and chlorophyll a diminished respectively to 70.6%, 67.7% and 40.9% of the initial concentrations in oyster treatments. These proportions were respectively 81.5%, 63.2% and 72.4% for ponds contacting barnacles, and 69.3%, 71.2% and 44.9% of the initial amounts in the combination of the two species treatment. Among three different densities used for treatments, medium density of oysters (0.54 oyster per liter) showed comparable effectiveness in nutrients and phytoplankton removal to the high density. Lower ammonia production along with imposing less costs and effort, as well as relatively equal ability; suggest the medium density of S. cucullata as the most suitable choice. Our results suggest that applying settlement ponds, and particularly with filter-feeder species such as S. cucullata, might mitigate the adverse impacts of shrimp wastewater, including coastal eutrophication, on adjacent ecosystems.

Capability of cyanobacterium, Microcystis aeruginosa, in the removal of cadmium and lead ions was investigated which was obtained after isolation from wastewater stabilization pond effluents. Influence of operational parameters including metal concentrations, pH, temperature and biomass dosage on removal efficiency was investigated. Also, applicability of closed reflux techniques for the digestion of cyanobacterial pellet was studied. A multi-phase washing method was developed in order to attain more elevated desorption efficiency. 1-5 washing cycles were repeated consecutively by the addition of new EDTA solution (4mM), stirring on mixer and centrifugation for each cycle. Maximum removal efficiency occurred at pH 7, temperature 28°C and biomass dosage of 0.2g for Cd2+ and corresponding values of 6, 25°C and 0.1g for Pb2+. In all tested concentrations of Cd2+ and Pb2+, extracellular absorption overweighed intracellular uptake with highest ratio of the former to the latter of 172 for Cd2+and 143 for Pb2+. EC50 values attained for Cd2+and Pb2+were 20 mg L-1 and 15 mg L-1, respectively. The closed-reflux digestion method was found as a suitable choice for cyanobacterial pellet digestion. Three-stage consecutive washing procedure devised in our study gave desorption efficiencies of 92 and 86 percent for Cd2+ and Pb2+ respectively as compared with values of 52 and 44 percent for Cd2+ and Pb2+, respectively obtained by the conventional washing procedure. This investigation verifies the possibility of employing M. aeruginosa for removal of Cd2+ and Pb2+ from aqueous and wastewater solutions.

This study investigated the activities of metabolic and immune enzymes in the hepatopancreas and muscle of the banana shrimp Fenneropenaeus merguiensis at different salinities (10, 15, 20, 25, and 30 ‰) and temperatures (21, 24, 27, 30, and 33°C).  The shrimp (mean initial weight, 1.72±0.25 g) were cultured at different salinities or different temperatures for 15 d. All treatments were conducted in triplicate. Results showed that glutamic pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT) activities in the hepatopancreas were the highest at a salinity of 20‰ (p<0.05). The GOT and succinate dehydrogenase (SDH) activities in the muscle were the highest at a salinity of 25 ‰ (p<0.05). The GOT and GPT activities in the hepatopancreas at a temperature of 24ºC were significantly higher than those at the other temperatures (p<0.05). The highest SDH activity in the muscle was observed at a temperature of  27 ºC (p<0.05). Different immune enzymes showed different responses to salinity and temperature. The highest superoxide dismutase (SOD) activity in the hepatopancreas, and the highest acid phosphatase (ACP) activity in the muscles was observed at a temperature of 24°C (p<0.05). By contrast, the lowest ACP activities in the hepatopancreas and muscles were observed at salinities of 25 and 20 ‰, respectively (p<0.05). These results indicated that suitable salinity and temperature can increase the metabolic enzyme activities, but the relationship of immune enzymes activities and ambient conditions is indeterminate.

A total of 2,400 Persian sturgeon fingerlings weighing 3.50-3.80 g were fed a diet composed of but different amounts of D-pro probiotics (Bacillus subtilis, B. licheniformis and yeast Saccharomyces cerevisiae). Fish were distributed in fiberglass tanks (1.80 × 1.80 × 60 cm) each containing 200 fish for 2 months. This research was conducted in Beheshti Sturgeon Hatchery Center, North Iran in the summer of 2016. The mean temperature of the water (21±2℃), pH (7.5±0.5), and aeration and oxygen concentration (6±0.5 mg L-1) were measured for 60 days. The calculated data were analyzed using one-way ANOVA test. Duncan test was used for comparing the means of the treatment. Results suggest that adding probiotics and yeasts to the diet had a significant impact on the percentages of hematocrit (PCV %), neutrophils and lysozyme (p<0.05). In addition, it was shown that the immunoglobulins in the T1 and T3 increased relatively to the control group. The amount of C3 and C4 complements were significantly increased by adding various sources of probiotics (p<0.05). Moreover, in terms of immune and biochemical parameters of the mucus sample, the interleukin 1 (T1 and T2) and lectin (T1 and T3) factors were improved. Also, in mucus samples, alkaline phosphatase and GPX all values measured in treated fish were lower than control group in various levels. These results show that application of two bacilli in combination form plus yeast may provide a better efficacy on the Persian sturgeon immune status.

Tubifex tubifex is a natural feed for many fish species, which still relies on natural catches. High nutrient contents culture media is needed to increase the availability and quality of T. tubifex. The aim of this study was to investigate growth performance of Nile tilapia (Oreochromis niloticus) larvae fed with T. tubifex cultured using different animal manures. Some profiles of T. tubifex nutrition (N, P, and K), Nile tilapia composition (proximate, essential amino acids, and fatty acids) fed with T. tubifex, Relative Growth Rate (RGR), Survival Rate (SR), biomass, feed intake, protein efficiency ratio, and water quality were analyzed. The results showed that tilapia fed with T. tubifex which cultured using various animal manures had a significant effect (p<0.05) on its nutrition, growth, biomass, and feed intake level compared to tilapia fed with T. tubifex which cultured without animal manures. However, it did not have significant effect in survival rate (p>0.05). The best treatment was obtained at T. tubifex cultured using 50 g/L of quail manure + 100 g L-1 of rice bran + 50 g L-1 of tofu waste (T2).

Over the last thirty years, the poor state of certain fish stocks in the Large Marine Ecosystem of the Canary Current gradually revealed the limits of the West African fisheries management. The Ecosystem Approach advocated in Mauritania, calls to change the perception of fisheries management to incorporate participatory management considerations total admissible catches (TACs) and fishing quotas. An experiment around, a total allowable capture of 800 tons of pink lobster (Palinurus mauritanicus) is at the heart of this approach using methodological tools of analysis / assessment of the economic performance of crawfish exploratory fishery. Survey results show that during the period from February 2015 to January 2016, the fishery was based on a total of 23 vessels. 52% is held by Mauritanian and the rest is chartered with European (EU) ship owners. The capture of the Mauritanian fishery is significantly higher than that of the European Union, respectively 393 tons against 390 tons. 98% of the overall production volume is in live lobsters, mainly for the European market. This production generated sales of 4.26 billion MRO Affairs. Overall, experimental rock lobster industry is an important macroeconomic activity. The Turnover (CA) represents approximately 5% of revenue from exports of the Mauritanian Fish Marketing Company in 2015 (US $ 268 million) and 13% of fishing GDP in 2014 (33.47 billion MRO, BCM 2015). Over two thirds of this amount (3.62 billion MRO) is generated by the (VA) Added Value 85% of turnover. The VA created by Mauritanian operators is 10% more than the VA created by European operators. The Fixed Annual Costs and the Estimated Gross Excess (FACEGE) represents 1.3 MRO billion or 32% of sales. More than half (MRO 896.6 million) in FACEGE is generated by Mauritanian. Experimental lobster industry creates 557 direct and indirect jobs. These jobs represent 10% of the industrial fishing jobs, globally estimated at 3764 Live 2014. It is estimated that the Mauritanian segment creates 25% more jobs than the European segment. This assessment of socio-economic performance of the exploratory fishery in Mauritania lobster is a first step towards a deeper understanding of its cost structure and its dynamics, necessary for the management of TACs and fishing quotas.

The aim of this work was to evaluate the influence of various lengths of starving periods on weight changes of different body parts and on chemical composition of the pike perch fillets. Forty cultured, market size (average bodyweight: 732.2±129.8 g), pikeperch of mixed sex were divided into 5 groups (n=8 in each), where one group were sampled at the starting time as a farm control, two groups were continuously fed for 3 and 6 weeks before slaughter, and the experimental groups were withdrawn from feed for 3 and 6 weeks before slaughter. Slaughter took place without any stress caused by transport or waiting times. Body parameters such as total body weights and the weights of 10 differentiated body parts, namely the gonad, the alimentary canal, the liver, the abdominal fat, the vertebral with unmatched fins, the head with the double fins, the two side fillets and the skins of both side fillets were monitored during the experimental period in each group. All body parts were defined and compared as the percentages of the total body weights. The chemical compositions of the fillets were examined by Weende analysis, thus dry matter, crude protein, crude fat and crude ash were measured. Increasing the length of the starving period reduced the body weight, mainly due to losses in intraperitoneal fat, although decreased fillet weights were found, caused by the depression of the intramuscular fat.

Beluga sturgeon (Huso huso), the largest freshwater fish, has attracted the attention of sturgeon culturists worldwide. The profitability of aquaculture beluga production mainly depends on physiologically suitable formulated diets. The objective of this research is to determine the optimal level of dietary selenium (Se) for beluga using the following parameters:  growth performance traits (WG, SGR, PER, and FER), body proximate composition, and serum biochemical and immunological indices (glucose, total protein, Ig M, lysozyme, ALT and AST). To this aim beluga (n=315; with initial weight of 15.66±0.77 g) were fed with diets supplimented with sodium selenite (0.18, 5.43, 12.6, 24.3, 37.2, 71.4, and 144 mg kg-1) for 10 weeks. Unexpectedly, all of the parameters exhibited considerable responses to the applied levels of Se. Growth performance indices displayed the highest values for the animals treated with diets containing 12.6 and 24.3 mg kg-1 Se, yet the lowest ones with 71.4 and 144 mg kg-1 (i.e., U-form response). Similar response was seen for crude lipid and protein content as well as for the activity of ALT and AST, whereas IgM and lysozyme did an anticline manner (i.e., the highest values in the midle Se levels). Moisture and ash contents and also serum total protein exhibited a Se-dose dependent increase. Based on the broken line regression model, optimal dietary Se requirement for juvenile beluga is about 18.2 mg kg-1. Taken together this study extends our knowledge on one of the most essential trace elements and its optimal level for incorporating into beluga diet. It  could also be a basic one in the sturgeon aquaculture industery.

In this study, the effects of diets (D1-3) including fish meal (FM), hazelnut meal (HM), soybean meal (SM), and phytase enzyme [- (0),+(1000 FTU)]  in varying rates (D1-, D1+; D2-, D2+; D3-, D3+)  were examined on nitrogen and phosphorus discharge based on the nutrition of rainbow trout (Oncorhynchus mykiss) juveniles. The study was conducted in tanks with 3 replicates for each group. In this trial, it was found that the differences among total-particle nitrogen, particle phosphorus, and total solid waste values released from the rainbow trout groups were insignificant; however, the differences between the values of total-dissolved phosphorus and dissolved nitrogen released were found significant (p<0.05).The interactions among the factors were determined as insignificant (p>0.05). Moreover, although there were increases in the total and dissolved phosphorus and dissolved nitrogen discharge in all groups fed with diets including phytase, the particle phosphorus discharge decreased (p<0.05). Based on the decrease in the amounts of hazelnut meal and soybean meal used in the diets, it was determined that there was a decrease in the amount of dissolved phosphorus released to the environment; besides, it was determined that it led to an increase in the amount of released dissolved phosphorus in all groups fed with diets containing phytase enzyme (p<0.05).

Chlorpyrifos (CPF) is used intensively as an insecticide. There is a high risk of interference with the aquatic environment due to unconscious use and has a negative effects especially fish. In this study, the responses of rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta fario) exposed to the same pollutants have been evaluated and compared in terms of target organs. Fish were exposed to different concentrations of CPF (0.25, 0.5, and 1 µg L-1) through 21 days. After the process oxidative stress [superoxide dismutase (SOD), catalase (CAT glucose-6-phosphate dehydrogenase (G6PD), glutathione reductase (GR), glutathione-S-transferase (GST), glutathione peroxidase (GPx)], acetylcholinesterase (AChE) and malondialdehyde (MDA) have been measured in gill, kidney and liver tissues. CPF exposure led to a significant changes in the enzyme activities and decreased AChE in all tissues (p<0.05). All antioxidant enzyme activities and MDA levels showed tissue-specific alterations (p<0.05). These results put forward a close relationship between AChE inhibition and chlorpyrifos concentrations. In addition to , CPF concentrations  caused oxidative stress and inhibition in all enzyme activities of two different trout species’ gill, liver and kidney tissues.

This research aimed to assess the effect methanol extract from Padina astraulis (Hauk , 1887) on biochemical response and digestive enzyme activities in grey mullet, Mugil cephalus (Linnaeus, 1758). A control diet without and three other empirical regimens were prepared with the addition of of P.astraulis extract (PE diet) at the incorporation levels of 5, 10 and 15 g kg-1 diet, respectively. Three hundred sixty grey mullet with an introductory mean weight of 0.82 g were randomly dispersed into twelve fish tanks and fed twice a day (09:00 and 17:00) for 60 days. After 60 days of the feeding trial, no significantly different was noticed in terms of survival rate between control and the groups supplemented with PE (p>0.05). Dietary PE significantly increased serum total protein, globulin levels and amylase, lipase and protease enzyme activities in treated fish (p<0.05). Moreover, there was considerable decline (p<0.05) in cholesterol, glucose and triglyceride levels in those fish which received PE diet over the control. The current research illustrates the appropriateness of P. astraulis extract as a novel dietary additive in grey mullet diet for improving metabolism of lipid and carbohydrate and enhancing digestive enzyme activities in grey mullet.

The main objective of this study was to evaluate the effects of dietary supplementation of Mix-Oil (including: Thymus vulgaris (%0.5), Origanum vulgare (2%) and Eucalyptus spp. (2.5%) essential oils) on growth performance, hepatic function parameters, tissue changes of rainbow trout and oxidative stability index of trout feed. Four groups of trout fish (with average weight 31.0±0.1 g) were fed with four diets containing: 0, 50, 200 and 400 ppm of Mix-Oil for 8 weeks. SGR, ADG, CF, TGC, DGC, RGR and BWI were significantly higher and also FCR significantly lower were observed in 200 and 400 ppm groups compared to 50 ppm and control groups (p<0.05). Significant increase in PER, LER, FCE and RFI in fish fed with 200 and 400 ppm Mix-Oil were observed compared with control and 50 ppm groups (p<0.05), while, no significant differences having been observed among different treatments in terms of AST and ALT level (p>0.05). An increase in the number of hematopoietic cells in the kidney and significant increase in the length of the intestinal villous and the number of related epithelium cells having been seen in the 400 ppm treatment group compared to the other studied treatment groups (p<0.05). By increasing the concentration of Mix-Oil, trout feed resistance has increased against oxidation. Although, the observed increments were only statistically significant in the 200 and 400 ppm Mix-Oil (p<0.05) compared to 50 ppm and control groups. The results suggested that dietary administration of Mix-Oil at the level of 400 ppm could improve growth performance of rainbow trout as well as increase the feed stability.

In this study, the impact of cage culture of rainbow trout (Oncorhynchus mykiss Walbaum), on benthic communities using biological indicators located along the coastal areas of the South Caspian Sea (Nashtarud region, Mazandaran Province, Iran) was investigated. Monthly samplings from 4 stations were carried out from January 2016 to May 2016. The physical and chemical characteristics of water were measured on a monthly basis. Sediment samples were taken using Ekman Grab. The ecological indicators such as Shannon–Wiener index of diversity, H, Simpson, S, and Margalef, R, was routinely used. The biomass-dominant faunal groups were Bivalve (146.16 g m-2(, Crustacea (24.5 g m-2) and Polychaeta (10.5 g m-2).The greatest variety of benthos was found under the cage and the lowest range was found150-300 m around the cage that was significantly different (p<0.05). Results of current study showed that, the percentage of sand was greater than that of silt and clay throughout the experimental period. Sediment organic matter (OM%) reached extremely high concentrations beneath the control (p<0.05), when compared surrounding area. A positive correlation coefficient was found betweethe Shannon–Wiener diversity index (Hchr('39')), and biomass of benthic organisms (p=0.001; r=0.684). According to results of species diversity, and amount of organic matter in the cage area, indicated that specific richness levels were in bad ecological statues.

The growth of the gastrointestinal tract of the larvae and juvenile of Alburnus chalcoides was studied after histological analysis using light microscopy, haematoxylin-eosin staining and the mouth development was scanned via electron microscopy. This study focuses on the morphology and histology of the mouth growth and digestive tract of A. chalcoides larvae to test the best weaning time for providing practical diet for fry based on the grade of their morphological aspects. It was observed that on the fifth day after hatching, the larvae mouth was opened. On the eighth day, the yolk sac was absorbed by two-thirds. On the same day, food is fed manually. Yolk sac was completely absorbed in 10th day. The histological base of the esophagus was formed by day 3. At day 3, the formation of enterocytes started. Also, the larvae hepatopancreas was formed on 5th day. According to the results, it was observed that after 8 days onwards, larvae of these fish can have a proper diet. At this day, the size of the mouth was 84 µm. when the lips were formed within 20 days and for the mouth angles 45ºand 90º, the food size for mouth, was 168 and 307 μm, respectively.

Differences of meristics, morphometrics characters and length-weight relationship were used to estimate the variability of wild and cultivated populations of the eastern river prawn, M. nipponense in the populations in Iranian Basin of the Caspian Sea. Three samples were collected from the northern and southern parts of the Caspian Sea in Iran. Ten measurements which made for each individual were size-standardized by allometric methods and principal component, and the resulting measurements were analyzed by cluster analysis and discriminant analysis (DA). The results of cluster analysis and DA indicated that the samples were clustered into two groups: the first group included the Caspian Sea sample; the second included the Anzali Lagoon and the third was Aquaculture farm sample. DA tests showed that morphometric, meristic and length-weight relationship differences among the two groups were significant. At least two morphologically populations of this species in the Iranian Basin of the Caspian Sea were determined. This study also suggested that external morphological traits in M. nipponense are variable and change markedly when exposed to different environmental conditions regardless of their geographic origin and that extensive variation was present among the populations studied.

Gender and sexual maturity stages of great sturgeon (Huso huso) were studied using blood plasma sex steroids hormones ratios (17β-estradiol (E2), testosterone (T) and 11-ketotestostrone (11KT)}. One hundred sixty reared great sturgeon aged (1-12 years) with weight and length 0.45 to 49.65 kg and 36-198 cm, respectively. For each gender, 80 individuals (20 fish in each maturity stage) were selected out of 650 fish. Hormone concentrations measured with commercial kits. All samples analyzed in duplicate and a separate standard curve run for each ELISA plate. The findings of this study showed that it is possible to separate male and female fish especially from the second sex maturation stage using T/E2 and 11KT/E2 hormone ratios. The results showed that the use of E2/T, E2/11KT ratios are very useful indices for sex determination and sexual maturity stages assessment in male reared great sturgeon, but T/11KT and 11KT/T ratios were not functional. Based on the results, the use of T/E2 and 11KT/E2 ratios were preferable to E2/T and E2/11KT ratios for recognition of different sex maturation stages in male fish. These hormone ratios were used to determine different stages of male sexuality with more than 95% precision, and less than 30% for females. In addition, despite strong correlation between length and weight of fish with hormone ratios, sex could not identified through this parameter. The results of the present study revealed that some sex steroid hormones ratios can determine the sex and sex stages of reared great sturgeon especially in males with high accuracy.