Iranian Journal of Fisheries Sciences
Volume:19 Issue: 5, Sep 2020

A 60-day trial with six diets (three different protein levels × two different lipid levels) containing 30, 35 and 40% protein with 10 and 15% lipid levels was conducted to determine the optimum dietary protein to lipid ratio and effects on growth performance and hematological indices of Aspikutum, Leuciscus aspius female×Rutilus frisii male. Two hundred and fifty two fish (31.2±0.4 g; mean±SEM) were distributed in 18 circular concrete tanks (400 L) and were fed 3 times daily according to their apparent satiation. The results showed that the highest growth rate was achieved when fish fed with diet containing 35% protein and 15% lipid. Lipid productive value was significantly decreased with increasing dietary lipid level. Number of red blood cells, white blood cells, hemoglobin concentration, hematocrit value, mean corpuscular volume, mean corpuscular hemoglobin, neutrophil and eosinophil were not considerably differing among rearing treatments, while mean corpuscular hemoglobin concentration was significantly higher in fish fed with diet containing 30% protein and 10% lipid. The percentage of lymphocyte increased with increasing dietary lipid level, whereas a decrease of monocyte percentage was observed with increasing of dietary lipid level. Dietary protein and lipid level, as well as the interaction showed no significant differences in total lipid, triglyceride, cholesterol and total protein levels. In general, this study has indicated that diet containing 35% protein and 15% lipid had positive effects on growth performance, while no effects on biochemical and hematological parameters was achieved.

The Persian Gulf and its shores are important and strategic areas with a large variety of fish species. Betanodavirus infection is known to be a serious threat to susceptible fish and causing economic damages to the fisheries and fishing industry. Concerning to isolation and confirmation of VNN virus in the Mullet fish (Chelon aurata and C. saliens) in the Caspian Sea and its damages on Mullet stock, probably transmission of VNN could be hazardous in marine fish industry such as cage culture. So, the aim of this article was to characterize the distribution of the Betanodavirus in Iranian southern waters and its transmission. Finally, the issues of the transmission of Betanodavirus infection between the wild and farmed fish of different regions of the Persian Gulf is discussed. The probability of the emergence of viral epidemics and even new and virus-resistant hosts has been investigated whereby the monitoring and surveillance program for tracing the disease and the detection of the Betanodavirus presence is required before clinical signs occur in the near future. Meanwhile, screening of various species of susceptible fish and the identification of the viral carriers as a strategic approach is recommended. In fact, Eco- epidemiological studies are needed and all efforts should be focused on control and prevention of probably virus contamination in the Persian Gulf and Oman Sea waters as one of the strategic points in the world.

Seasonal variations of proximate compositions and fatty acids of tench (Tinca tinca) captured from Seyhan Dam Lake were investigated. The results showed that seasonal fatty acid compositions of tench fillets in July, August and November ranged from 29.59% to 33.71% for saturated fatty acids (SFA), from 20.50% to 21.69% for monounsaturated fatty acids (MUFAs) and from 26.50% to 41.85% for polyunsaturated fatty acids (PUFAs). Lipid contents of tench fillets in all seasons were statistically different (p<0.05). The major fatty acids of tench sampled in different seasons were palmitic acid (16:0), stearic acid (18:0), palmitoleic acid (16:1ω7), oleic acid (18:1ω9), linoleic acid (LA, 18:2ω6), arachidonic acid (ARA, 20:4ω6), eicosapentaenoic acid (EPA, 20:5ω3) and docosahexaenoic acid (DHA, 22:6ω3). The proportions of DHA ranged from 5.51% to 17.33%. DHA+EPA compositions of tench fillets were in the highest level of 22.47% in November. The highest ARA content was determined in November at 10.88%. The results showed that tench is a good protein and fatty acid source in human nutrition.

The present study examined the effects of chitosan (Ch) and chitosan combined with sodium tripolyphosphate (Nch) nanoparticles as coating materials for Cynoglossus arel fillets during superchilling storage. Treatments included the following: C (untreated, control samples), AC (treated with 1% glacial acetic acid, acid control), Ch (treated with 2% w/v chitosan solution, Chitosan) and Nch (treated with 2% w/v chitosan and 2% sodium tripolyphosphate, Nanochitosan). Nch and Ch coatings significantly were effective on total mesophilic counts (TMC), psychrotrophilic bacteria (PTC) and Enterobacteriaceae. Production of total volatile bases nitrogen (TVBN) and trimethylamine (TMA) for Nch and Ch samples was significantly lower than in control samples during storage. The thiobarbituric acid (TBA) and free fatty acids (FFA) exhibited an increasing trend (p<0.05), whereas the total sulfhydryl (SH) decreased (p<0.05) with increasing storage time. The results indicated that Nch and Ch can be used for preservation of quality properties of fish samples. The Nch was better than ones Ch in reducing lipid oxidation of fillets and bacterial contamination.

Aeromonas hydrophila is a gram-negative bacterium which associated with gastrointestinal diseases and septicaemia. This pathogenic bacterium has several virulence factors ranging from pili to the excreted protein which called (Aerolysin) with minor and major effects, respectively. Additionally, Aeromonas hydrophila is a widely distributed bacterium that commonly causes ulcers in cyprinid fish such as carps and secondary diseases in humans as well. In the present study, characteristics and haemolytic activities of the recombinant Aerolysin protein and optimal conditions for cloning are determined using the synthesized cloning/expression Aerolysin gene, assembled into the Escherichia coli BL21 (DE3) through pGEX-6P1 vector, using SDS-PAGE and western blotting techniques. The results declared that, the Aerolysin gene (1482 bp) was cloned by transforming the recombinant pGEX-6P1 vector into Escherichia coli BL21 (DE3) as a prokaryotic expression host. The SDS-PAGE results indicated that the estimated protein size was 54 KDa. Recombinant Aerolysin protein synthesis at both selected temperatures, 25°C and 37°C, indicated that 1 mM of isopropyl-β-D-thiogalactopyranoside (IPTG) was the optimum concentration for induction. However, the recombinant protein was unable to synthesize in the absence of IPTG inducer. Western blot analysis indicated the efficient sensitivity and specificity of the recombinant Aerolysin protein. In conclusion, the recombinant protein showed potential advantages for immunoassay approaches in order to decrease the economic losses caused by disease in the aquaculture industry.

The study of benthic macroinvertebrate communities is one of the most common methods for assessing the effects of stresses on the biological conditions of aquatic ecosystems and water quality monitoring. This research was conducted to study the changes in the macroinvertebrate communities in the Shanbeh-Bazar River, Anzali International wetland and the effects of environmental factors. Sampling was done seasonally from spring to winter in 2017 from the. Bio-indicators, MDS, PCA, correlation and ANOSIM were used in this study. A total of 3963 macroinvertebrate belonging to 3 phyla, 9 orders of 17 families were identified. The two families of Chironomidae and Tubificidae were the most abundant, and the dominant group of the Shanbeh-Bazar River. The bio-indicators analysis varied from medium pollution to heavy pollution at different stations. MDS plot showed that sampling stations were clearly separated into 3 groups. ANOSIM and PCA analysis were shown that the human activities and urban wastewater effects on benthic communities such as increasing the resistant families (Tubificidae). The increasing of agricultural activities and the destruction of marginal forests at Stations 3 and 4 were caused the abundance of Chironomidae and Tubificidae increased. Since the Shanbeh-Bazar River has urban disturbance, especially wastewater inputs, agriculture, fishing and recreational boats, macroinvertebrate diversity decreased with increasing contaminants and stresses, led to an increase in resistant species. With the increase of agricultural and the destruction of marginal forests, the amount of organic matter increased in the water body. Anthropogenic activities are indicated to have the most negative effects on the river ecosystem. Thus, it was concluded that the river health of Shanbeh-Bazar River is within unacceptable range.

This study was performed to evaluate the effectiveness of three different conditions of osmotic pressure (325, 365 and 385 mOsm kg-1) in combination with dimethyl sulfoxide (DMSO) and NaCl or glucose on spermatozoa DNA damage, rate and duration of motility. Sperm was collected from eight healthy mature Mesopotamian catfish, evaluated microscopically and pooled at 25 °C. The pooled sperm samples were diluted to a final concentration of 1/3 (sperm/diluents) in  NaCl and glucose based extender (10% cryoprotectant and 10% egg yolk (EY) into 80% diluents) and separated into groups of 3 different osmotic pressures (325-365-385 mOsm kg-1). Equilibrated sperm was frozen in 0.25 mL straws. Sperm samples were tested for post-thaw sperm motility, duration of motility, DNA damage, and apoptotic index. The highest spermatozoa motility rates were obtained with glucose and NaCl diluents at osmotic pressures of 365 and 385 mOsm kg-1 (p<0.01). The spermatozoa motility duration was found to be the highest in glucose and NaCl diluents at 365 mOsm kg-1 osmotic pressure (p<0.01). The post-thawing live spermatozoa rate was determined to be the highest in the sperm frozen with glucose at 385 mOsm kg-1. The apoptotic cell rate was determined to be the highest in the sperm frozen with glucose at 385 mOsm kg-1 osmotic pressure. The necrotic cell rate was found to be the highest with 2.08±0.39% when frozen with the glucose diluent at 325 mOsm kg-1 pressures. It is concluded that the glucose solution with low osmolality had a harmful effect on the spermatozoa.

An initial experimental study was conducted to evaluate the effects of binaural beats on fish growth performance. A 90-day trial with four triplicate groups was conducted with 240 zebrafish, Danio rerio, under aquarium conditions. Binaural beat file complexes were played for each aquarium using computer controlled directional speakers for 0 min d-1(Control), 90 min d-1(Group 1), 180 min d-1 (Group 2), and 270 min d-1 (Group 3). Fish with an average initial weight of 0.26±0.001g were fed twice a day on standard commercial feeds meant for ornamental fish. Body weight gain improved significantly and the highest final body weight was observed in Group I, followed by the other two treatment groups, and finally the Control. Specific growth rate data similarly resulted in significant differences (p<0.05). The highest Average Daily Growth (ADG: 0.26±0.038) and Specific Growth Rate (SGR: 0.31±0.034) values were found for Group I, while other treatments were found statistically equal and all represented significantly higher values than the Control. Improved Feed Efficiency (FE) was also observed in Group I. These results support the enhancing effects of binaural beats on growth performance and feed utilization in D. rerio. The system and the procedure followed in this study hold the promise of being regarded as eco-friendly and non-invasive growth promoters for fish.

This study was undertaken to investigate the diversity, abundance ratio, and distribution of the fish species and to record the water quality of Konhaye Stream, district Dir Lower, Pakistan. A total of 16 fish species were recorded, belonging to 4 orders (Cypriniformes, Channiformes, Siluriformes and Mastacebilformes), and 5 families including Cyprinidae (Schizopyge esocinus, Racoma labiata, Cyprinion watsoni, Cyprinus carpio, Barilius pakistanicus, B. vagra, B. modestus, Crossocheilus diplocheilus, Garra gotyla, Puntius ticto, and P. sophore), Channidae (Channa punctatus and Channa gachua), Nemacheilidae (Schistura macrolepis), Sisoidae (Glyptothorax punjabensis), and Mastacembelidae (Mastacembelus armatus). Different ichthyo-diversity indices [Simpson’s biodiversity index (D=0.918), Simpson’s reciprocal index (1/D=1.088), Simpson’s evenness index (E1/D=0.068), species richness (S), Shannon-Weiner’s index (H′=3.775), Menhinick’s index (Dmn=0.804), and Margalef’s index (Dmg=2.510)] were calculated for the stream. The physicochemical parameters [temperature (23.125±3.514℃), dissolved Oxygen (9.003±0.627 mg L-1), pH (7.333±0.201), turbidity (76.5±6.403 NTU), electric conductivity (201.68±11.31 µs cm-1), free CO2 (124.75±9.912 ppm), total dissolved solids (126.1±9.477 ppm), total alkalinity (4.325±0.171 mg L-1), total suspended solids (127.1±6.864 ppm), total hardness (5.225±0.341 mg L-1), salinity (42.25±6.292 ppt), calcium hardness (2.975±0.670 mg L-1), magnesium hardness (105±9.954 mg L-1), potassium (0.0145±0.001 mg L-1), sodium (16.55±3.861 mg L-1), chloride (1.825±0.727 mg/l), and nitrate (0.053±0.006 mg L-1) level] were monitored and found to be in varying but permissible ranges. The stream was found to be harboring a number of economically valuable fish species. An exotic fish species, C. carpio, was found well flourished, indicating the potential of the stream to be used for mitigating the declining ichthyofaunal diversity in the main nearby rivers. Two species, P. sophore and P. ticto, were recorded for the first time from the district. Proper management, appropriate fish stocking, and implementing environmental/fishing laws are suggested for the maintenance of the diversity and alleviating anthropogenic stress/threats.

The population structure of Aphanius mento in the Seyhan Reservoir was studied on the basis of 834 fish specimens (516 males and 318 females) caught on a monthly basisbetween September 2013 and August 2014. Fish were collected using dip nets of tulle with a 1mm mesh size. The maximum age of fish was found to be 4 years for both sexes combined, the 1 year old age group comprised 62.20% of male samples. The overall sex ratio of females to males was 1:1.62. Von Bertalanffy growth parameters were L∞=54.33 mm, K=0.399 year-1,  t0 =-1.168 years for females, L∞ =52.72 mm, K=0.397 year-1, t0=-1.137 years for males, and L∞=56.50 mm, K=0.386 year-1,                t0=-1.257 years for both sexes. The length (TL) - weight (W) relationship was W= 0.00051xTL2.635, (r= 0.965) for males, W=0.00088xTL2.464, (r= 0.987) for females and W=0.00066xTL2.554, (r = 0.974) for both sexes. Condition factor ranged from 1.696 for males and 1.613 for females to 1.664 for both sexes. The mean condition factor (CF) was not significantly different between the sexes among all fish during different months (p>0.05). The present study represents the first comprehensive information on the population structure of A. mento in the Seyhan Reservoir. The results of this study will contribute to the population management and conservation of this species and be useful in increasing knowledge on its ecology and biology.

It is known that zeolite, tested in animal feeds in recent years, has a positive effect on fish growth and many physiological parameters. For this purpose, rainbow trout (Oncorhynchus mykiss) was fed with feeds containing zeolite at different rates (1%, 3%, and 5%) for three months in the present study. Fish growth parameters (live weight gain, specific growth rate, feed conversion rate, condition factor, and mortality rate) and hematological indices (total erythrocytes count (RBC), total leucocytes count (WBC), hemoglobin (Hb), hematocrit (Hct), total plate count (PLT), erythrocyte sedimentation rate (ESR), mean cell hemoglobin concentration (MCHC), mean cell hemoglobin (MCH), and mean cell volume (MCV) were examined monthly during the experiment.
At the end of the feeding period, the changes in growth parameters were determined, and only condition factor was found statistically significant (p<0.05). The highest condition factor calculated was 0.70 in group Z3 at the end of the study. In the hematological indexes, different ratios of zeolite added diets were found to cause a change in the blood indices, of which WBC, ESR and MCV values were statistically significant (p<0.05).

The sea cucumber (Bohadschia ocellata) is a species with great density, reproduction rate and growth in the Persian Gulf. A Very  few human consumption in Islamic countries makes this species a good choice to be used as a supplementary or stimulant ingredient in cultured aquatic animals. The present study evaluates the effects of dietary levels of B. ocellata meal on growth performance, blood biochemical parameters, digestive enzymes activities and body composition of Pacific white shrimp (Penaeus vannamei). White shrimp juveniles (6.6±0.1 g) were fed with different levels of the B. ocellata meal (0, 2, 4, 6, and 8 % of the diet) during 8-weeks period. According to the results weight gain, specific growth rate, and daily feed intake trends showed significant (p<0.05) increase with increasing level of sea cucumber meal from 0% to 4%. The greatest feed conversion ratio and least protein efficiency ratio were recorded in the 8% treatment. In blood biochemical outputs, the least cholesterol and the highest glucose levels were recorded for the 4% and 6% treatments, respectively. Digestive enzymes activity assessments showed that protease activity was significantly increased from 4% to 8% treatments. In general, adding 4-6% of B. ocellata meal to commercial diet of P. vannamei juveniles clearly improved some body biochemical activities such as protease enzymes activity and blood cholesterol content, and enhanced growth performance of white shrimp.

Due to numerous reasons, marine-obtained resources have attracted the interest of researchers. One of the subjects attracted the interest of researchers in recent years in the field of biologist marine algae due to their nutritional value, their benefits for health and their biological activities. In this study, the powder was extracted using acetone, then the extract purified by silica gel column chromatography with n-hexane and ethyl acetate combination to isolate the steroid compounds. Isolated compound was run through TLC and sprayed with vanillin-sulphuric acid reagent to detect the steroid compounds and profile of isolated compounds obtained by gas chromatography (GC). Antibacterial activity of steroids extracted of green algae Ulva fasciata from Qeshm Island in the Persian Gulf were assessed (in vitro). The antibacterial activity of the fractions was determined by Broth Dilution Methods against clinical Gram-negative bacteria: Escherichia coli, Pseudomonas aeruginosa, Salmonella. typhi and Gram-positive bacteria: Staphylococcus aureus, Bacillus subtilis, Bacillus cereus. The steroids; cholest-7-en-3ol and cholestan-3-one, cyclic 1, 2-ethanediyl acetal compounds in column fraction were identified by GC. The results showed the minimum bactericidal concentration (MBC) of the cholest-7-en-3ol and cholestan-3-one, cyclic 1,2-ethanediyl acetal for S. aureus and Bacillus cereus were 500 μg ml-1, the MBC of the cholest-7-en-3ol for B. subtilis was 500 μg ml-1 and 1000 μg ml-1 detected for cholestan-3-one, cyclic 1,2-ethanediyl acetal. The compounds had neither antibacterial activity on gram negative bacteria. Based on our results, extracted steroids from U. fasciata can be considered as a source of novel antibiotics.

Fucoxanthin contents of four species of brown seaweeds (Dictyota indica, Padina tenuis, Colpomenia sinuosa and Iyengaria stellata) from intertidal zone of Qeshm Island, Persian Gulf were assessed in summer and winter of 2016. In addition, some physicochemical properties (pH, temperature, salinity and conductivity) of seawater were monitored on the same time. The antibacterial activity of algal extracts was determined by disc diffusion assay, minimum inhibitory and minimum bactericidal concentration tests; and the antioxidant activity through ferric reducing antioxidant power method. The fucoxanthin contents of the studied seaweeds were higher in winter. D. indica showed the highest amount of fucoxanthin (approximately 462.79 and 210.72 µg/g) in both seasons, which makes it commercially applicable e.g. in food and pharmaceutical industries. Furthermore, D. indica, I. stellata, P. tenuis and C. sinuosa showed a strong ferric reduction power in both seasons. Considerable inhibition zone against gram negative (Escherichia Coli: PTCC1330) and gram positive bacteria (Staphylococcus aureus: PTCC1112) were also observed.

The main objective of this study was to evaluate the pathogenicity of isolated Yersinia ruckeri from Caspian trout. Y. ruckeri specimens were isolated from infected rainbow trout farms located in north of Iran. The identification was confirmed by biochemical tests and 16s rRNA gene sequencing. The pathogenicity test was carried out to determine the virulence of the Y. ruckeri by IP injection, and histopathological and hemato-biochemical changes were evaluated pre and post challenge. Based on the results, LD50 were calculated as 1×105 CFU ml-1, while 1×107 CFU ml-1 caused 100% mortality after 10 days in the experimental groups. The main histopathological changes were seen in liver, kidney, spleen and intestine, including erosion and necrosis, infiltration of inflammatory cell, hyperplasia and catarrhal enteritis in the infected organs. Also, a significant decrease in glucose, RBC counts, Hb values and HCT percentage and significant increase in the WBC counts, neutrophils percentage, AST, ALP and LDH values were observed in infected fish after challenging. Finally, Caspian trout is susceptible to Yersiniosis and can play important role in transmission of Y. ruckeri to cultured and wild fish.

The isolation of Aeromonas hydrophila from Oncorhynchus mykiss reared in the farms was the aim of the present study. Ninety samples were collected aseptically from the infected fish with signs of hemorrhagic septicemia in gill and skin, exophthalmia, dropsy and 36 water samples were sub-cultured on Tryptic Soya Agar (TSA), as well as kidney. The genotyping by PCR method was used to amplify the gene of 16 SrDNA using primers 27F and 1492R as primer pairs to achieve an approximate length of 1500 bp. The identified motile Aeromonas species were sequenced with electrogram chromas format in chrome version 1/41 software and a phylogenetic tree was drowned by MEGA5.1 software. The results showed that 19% of 24 isolated from gram-negative bacteria were detected as Aeromonas, which the sequencing results revealed that all the isolated bacteria had 99% similarities with the standard A. hydrophila. The results of environmental factors showed when the levels of dissolved oxygen have decreased and the levels of nitrite and ammonia have increased throughout the year, Aeromonasias is increased. Also, when the water has gone alkaline due to increased ammonia, the disease has increased. It may be concluded that fish farmers should take proper management practices to avoid such disease in cultured fishes especially rainbow trout and to get rid of the infection by such serious bacterial pathogen like Aeromonas hydrophila by improving their culture strategy and culture ecosystem.

Despite studies on the effect of androgens in female teleost fish, many aspects of androgen supplementation in female sturgeon gametogenesis remain elusive. The aim of the study was to investigate the immunological and physiological responses of 4-year-old previtellogenic great sturgeon (Huso huso) (body weight 5580±165 g) to 11-ketotestosterone (11-KT) implants. The fish were divided into two groups of 6 fish: 11-KT group, which received a single intraperitoneal implant of 2.5 mg 11-KT and a placebo group, which was implanted without 11-KT for 56 days. Just before implantation and on days 21 and 56 post-implantation, serum samples were taken to measure immune parameters (IgM, C3 and C4) and some related biochemical and hematological indices. Results showed a significant reduction in IgM concentrations after implantation in both the 11-KT and placebo groups (p<0.05). The concentration of C4 showed an opposite trend and significantly increased in both the placebo and 11-KT groups (p<0.05). The concentration of C3 and IgM to protein (IgM/p) ratio showed no significant differences during the experiment (p>0.05). Serum testosterone (T) levels in the 11-KT implanted group increased significantly on days 21 and 56 post-implantation (p<0.01). The albumin to globulin ratio showed no significant change in the 11-KT group (p>0.05), but a significant difference was observed in the placebo group during the study period (p<0.05). In hematological parameters, the number of red blood cells significantly increased after 56 days compared with that after 21 days in both experimental groups (p<0.05), while white blood cells significantly increased in the 11-KT group after 56 days (p<0.05). The results indicated that implantation with or without 11-KT could suppress some immunity parameters of great sturgeon.

This study was performed in order to determine the antibacterial activity of oregano, Origanum vulgare extract (OVE) and its nano extract (NOVE) on Streptococcus iniae in rainbow trout in vitro and in vivo. Extraction was done under standard percolation method. Then OVE and NOVE were screened to identify their antimicrobial activity against Streptococcus iniae by using disk diffusion assay and challenge methods. Also, the MIC and MBC values for OVE and NOVE were determined by micro dilution method. Furthermore, the antimicrobial effect of OVE and NOVE were examined by feeding rainbow trout fingerlings, with O. vulgare extract and its nano extract and florfenicol as a positive control. Then, all fish were injected intraperitoneal with S. iniae suspension in 3×108 CFU ml-1 concentration. Mortality rate was investigated for next 14 days after injection; then the spleen of fish samples removed to determine bacteria total count (SBT). In vitro results showed that OVE and NOVE had antimicrobial activity which was higher in NOVE. The inhibition zone of NOVE (26.066 mm) was significantly greater than OVE (21.7mm) (p<0.05). Also, the MIC and MBC values with high efficacy against S. iniae in NOVE treatment group were 0.25 and 0.5 mgmL respectively, which was lower than OVE treatment values (p<0.05). In vivo results showed that the mortality rate and SBT was significantly lower (p<0.05) in the fish fed with NOVE than OVE and the control group (p<0.05). These results indicated that the Origanum vulgare extract and its nano extract supplement are satisfactory as a prophylactic measure against rainbow trout streptococcosis and also for fish health improvement.

The Caspian seal (Pusa caspica) from Phocidae family is the only living mammal that exclusively inhabits the landlocked Caspian Sea. This study was first of its kind conducted on the Caspian seals in the southeastern region of the Caspian Sea from 2010 to 2016. Seasonal observations, gender, maturity, biometric parameters and condition index of each observed Caspian seal were studied. Totally 74 live Caspian seals including 42 males and 32 females were observed in this study. The Caspian seals observed in autumn were significantly greater in number than in the other seasons (p<0.05). There was no significant difference between the number of the males and females (p>0.05), however, the number of juvenile seals were significantly more than adults (p<0.05). This study revealed no significant difference in each biometric parameter and condition index in different seasons, and also between female and male Caspian seals (p>0.05). A significant difference was observed between adult and juvenile seals in biometric parameters (p<0.05), however condition index was not significantly different (p>0.05). Since Caspian seals are listed as endangered species in the IUCN Red List, further research is required to understand the status of this population and conserve the only mammals of the Caspian Sea.

Vitamin E (VE) is one of the most important micronutrients that influence the performance of shrimp reproduction. The effects of different dietary VE levels (0, 100, 300 and 500 mg kg-1) were investigated on the reproductive performance and vitellogenin (Vg) gene expression in Litopenaeus vannamei females which were co-fed with fresh food (two times daily) or experimental diets (two times daily) for 30 days. Sampling was carried out at the first day of the trial, prior to eyestalk ablation ( ESA ) (day 21) and after ESA (day 30). The reproductive parameters including hepatopancreatic index, absolute fecundity, egg diameter, latency period, and Vg gene expression were higher in the shrimp fed with VE supplemented diets than the control group (p<0.05). After ESA, the Vg gene expression significantly increased in all groups (p<0.05). As a measure of reproductive status of Pacific white shrimp, the present study evaluated correlations of Vg gene expression in hepatopancreas with the number and diameter of oocytes in gonads. Accordingly, Vg is a precursor of vitellin, which is the major yolk protein accumulated in ooplasm. These results provide evidence that dietary VE with 300 mg kg-1 may present a novel strategy and play a positive impact on reproductive performance and Vg gene expression of female shrimp.

Echinodermata are one of the most important branches of invertebrate in marine ecosystems, which today are also known as a rich source of natural products with biological properties. Most of these properties belong to compounds with a terpenoids structure. According to the biological properties of sea cucumbers in the Persian Gulf, this scientific study investigates the antibacterial properties of lanosterol compounds extracted from Holothuria leucospilota in Hengam Island in the Persian Gulf. The sea cucumber powder was extracted using acetone, then the extract purified by silica gel column chromatography with n-hexane and ethyl acetate combination to isolate the terpenoid compounds. Isolated compound were run through TLC and sprayed with vanillin-sulphuric acid reagent for detection of terpenoid compounds and profile of isolated compounds obtained by gas chromatography (GC). The lanosterol teriterpenoids compound in column fraction was identified by GC. Antimicrobial properties were evaluated by dilution test on bacterial strain Escherichia coli, Pseudomonas aeruginosa, Klebsiella nemonya, Proteus vulgaris, Salmonella typhi, Staphylococcus aureus, Bacillus subtilis, Bacillus cereus and Nocardia brazilinus. This compound show antibacterial activities against gram-positive bacteria (B. subtilis, B. cereus and S. aureus). Antibacterial results of lanosterol authenticated that could be an efficacious compound in antibiotics production

Alcian blue binds to the proteoglycans components of the extracellular matrix in chondrocytes and turns the cartilage color to blue. Alizarin red stains free calcium and certain calcium compound to a red or light purple color. This procedure is a useful tool to study the skeletal development in several fish species and then to precociously diagnose malformations in cartilages and bones development in small larvae and eventually to better characterize the effect of different environmental and/or nutritional factors on the ossification status of specific skeletal components. It should be noted that according to different species, the modifications in the protocol are still reported. In this experiment 520 specimens of rainbow trout in different life stages from one-day post hatching (dph) to 30 days, 1.5±0.1 and 3.5±0.5 cm in length have been studied. The double staining protocol for developing rainbow trout has been defined based on diverse published protocols. For an optimal staining protocol design, the incubation times of the different solutions were adjusted. Then the photos of stained specimens have been used to study and compare. The detection of cartilages and bones helps to understand the ontogeny of fish skeletal structure and the effects of environmental factors on bone density and plasticity. In addition, given the importance of skeletal and musclechr('39')s interactions, it is possible to conduct a survey on specific factors to change the skeletal tissues.

The potential of milky mangrove Excoecaria agallocha leaf extracts has been utilized in traditional medicine in various parts of the world. Blood is an important indicator of health and is a pathological mirror of the entire body. Therefore, the effects of E. agallocha leaf extract on hematology indices of hybrid tilapia (Oreochromis niloticus) were investigated. Experimental fish were randomly divided into seven groups. Groups 1 to 5 were fed medicated feed at five different concentrations (10, 20, 30, 40 and 50 mg kg-1) of E. agallocha leaf extract. Group 6 was given Flumequine (25 mg kg-1) and group 7 was fed with untreated feed (control) for 28 days before they were intraperitoneally exposed to 4x105cfu CFU ml-1 S. agalactiae. The results revealed that the group fed medicated feed at 50 mg kg-1 was the most effective concentration and showed no significant difference (p>0.05) compared to control and antibiotic groups on blood parameters (red blood cell, globulin, total serum protein, mean cell hemoglobin, and mean cell hemoglobin concentration) with the highest survival rate 99.67% within experimental groups. Overall, our results indicated the potential of E. agallocha could prove to be a hematological profile enhancer which can help fish combat bacterial infections. It was concluded that increase in the white blood cell count observed in fish administered with E. agallocha leaf extract at 50 mg kg-1 suggests that E. agallocha extract contains agents that could stimulate the production of leucocytes and serve as an immune booster and prevent the risk of anemia.

Feeding strategies are typical traits reflecting the adaptation of species to environmental conditions. The aim of this paper was to find proof that functional feeding groups of benthic macroinvertebrates can be unitized as surrogates for biological assessments. The composition and abundance of functional feeding groups of the benthic macroinvertebrate assemblages were surveyed along the Zarin-Gol River, Iran during winter and spring of 2016. Benthic samples in 3 replicates were collected using a Surber sampler (900 cm2 area) from 5 stations (in agricultural land, rural area, forest land, fish culture site and reference site). Ten environmental parameters including (temperature, dissolved oxygen, pH, Electric conductivity, etc.) of each station were assessed. A total of 901 individuals belonging to 30 families and 9 orders were identified. In terms of relative abundance, Collector/Gatherer and Collector/ Filterers were the predominant groups at most sampling stations. Shredders had low abundance in all stations and were absent in station two. Principal component analysis and cluster ordination showed that there are two distinct groups of benthic macroinvertebrates and stations. The  implication of the observed pattern of variation in the abundance of functional feeding groups was discussed regarding the functions of the ecosystem and water quality assessment.

All Spatoglossum and Stoechospermum species in Persian Gulf and Oman  Sea, Iran, have been so far identified via classical taxonomy. In this study classification of two genus of brown algae (Dictyotaceae) including Spatoglossum and Stoechospermum have been investigated. We combined the cytoplasmic DNA sequences data of plastid rbcL and psbA with morphological information. Based on the constructed phylogenetic trees on the sequences data of these two genes the collected specimens from the Iranian coastlines made two distinct clades which were grouped with two species Stoechospermum polypodioides and Spatoglossum crassum with high to full bootstrap values. So we approved the presence of Stoechospermum polypodioides and  Spatoglossum crassum as new record for the algal flora of Persian Gulf in Iranian coastlines.

All Spatoglossum and Stoechospermum species in Persian Gulf and Oman Sea, Iran, have been so far identified via classical taxonomy. In this study classification of two genus of brown algae (Dictyotaceae) including Spatoglossum and Stoechospermum have been investigated. We combined the cytoplasmic DNA sequences data of plastid rbcL and psbA with morphological information. Based on the constructed phylogenetic trees on the sequences data of these two genes the collected specimens from the Iranian coastlines made two distinct clades which were grouped with two species Stoechospermum polypodioides and Spatoglossum crassum with high to full bootstrap values. So we approved the presence of Stoechospermum polypodioides and Spatoglossum crassum as new record for the algal flora of Persian Gulf in Iranian coastlines.

A feeding trial was performed to investigate the effects of the partial replacement of fish meal with distiller’s dried grains with solubles (DDGS) on growth, feed assessment, economic assessment, digestibility of diets, as well as liver and intestinal histology of rainbow trout (Oncorhynchus mykiss). Four isonitrogenous and isocaloric diets were prepared using DDGS in rates of 0%, 10%, 20% and 30% (Control, DDGS10, DDGS20, and DDGS30, respectively) instead of reducing the fish meal content. Triplicate groups of 25 rainbow trout (mean initial weight 19.88±0.02 g) were fed with the diets for 84 days. The results revealed that dietary DDGS30 had the highest final weight and specific growth rate. Feed conversion and protein efficiency rates were similar among the dietary treatments. Economic conversion ratio was reduced depending on DDGS increase in diet that resulted in an increased economic profit index. The apparent digestibility of the diets did not differ significantly among treatments. There were no significant differences in the diameter of hepatocyte nuclei but there was a detected amount of vacuolization in the hepatocyte cytoplasm of fish fed  the dietary DDGS20 and DDGS30 diets. Distal intestine histomorphometric parameters were unaffected by dietary treatments, however, increased lamina propria width was observed as the rate of DDGS increased in diets. These results indicate that DDGS can be added to rainbow trout diets by up to 30% without negatively affecting growth performance, diet digestibility, as well as the histology of  the liver and intestine.

This study was carried out to investigate the effects of enriched Artemia with selenium nanoparticles on growth and survival rates and biochemical factors in guppy Poecilia reticulata larvae over a six-week period. Guppy larvae with a mean weight of 33.55 mg in three treatments and one control group (each with three replicates) were fed with Artemia franciscana enriched with 5, 10, and 50 mg L-1 selenium nanoparticles. In terms of growth indices, significant differences were observed among treatments in length increment, weight gain, specific growth rate and survival rate (p<0.05). There was no significant difference in condition factor (p>0.05). Regarding biochemical factors, significant differences were observed between treatments. Artemia - fed treatments enriched with 5 and 10 mg of selenium nanoparticles (treatment 1 and 2) showed the lowest and in the treatment fed with Artemia - enriched 50 mg nanoparticles (treatment 3) showed the highest levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, creatinine phosphokinase and lactate dehydrogenase. The highest total protein content was observed in treatment 2, which was significantly different from the other treatments (p<0.05). Overall, if the goal of using selenium-enriched Artemia in fish larval diet is to increase survival and growth rate and improve biochemical indices, the use of selenium nanoparticles at the levels of 5 and 10 mg L-1 is appropriate for enriching Artemia to feed the fish larvae.

This study was carried out at Saros Bay, between June 2011 and July 2013 to determine hook selectivity of bottom longlines used in European hake (Merluccius merluccius, L. 1758) fishing. Throughout the study; thick type, 6, 7, 8 and 9 sized flat hooks were used between 150 and 400 m depth. 36 fishing operations were carried out and 222 fish were caught using 7200 hooks in total. Depending on the size of hooks; number 8 was the most efficient hook that has caught 114 fish and number 6 was the least efficient one that has caught only 14 fish. The SELECT method is used in the determination of the selectivity parameters. Bi model has given the best fit according to selectivity analysis of five different models. Optimum catching lengths found were 60.09 cm for 6 number hook; 51.45 cm for 7 number hook; 46.43 cm for 8 number hook; 40.11 cm for 9 number hook, in Bi Model model. Minimum size limit for European hake is 25 cm in Turkey. Considering the minimum size limit, use of hooks with gapes larger than number 9 hook (11.75 mm) used in this study is suggested.

The utilization of present-day advancements is another methodology that has been especially considered. In such manner, the combination of nanotechnology and food science has prompted the development of numerous capacities in the nourishment segment. This study was conducted to evaluate the antimicrobial effect of nano-silver packaging at two refrigerator temperature (4 and 8) in Tilapia to evaluates the total viable microbe, Escherichia coli, Staphylococcal aureus, and psychrophilic bacteria. 10 grams of washed fish put in 5 groups treated with A: 1%: B 3%, C: 5%, D: 7% nano silver coating and E: control group and stored for 0, 3, 7, 14 and 30 days. The biochemical analysis of total volatile nitrogen and peroxide was investigated. The best nano-silver percentage reported as 7 %. The result of this research demonstrates that the antimicrobial properties of nano silver for various bacterial species are exclusive. We believe that nano-silver packaging improved the quality and shelf life of fish.

This study was conducted to evaluate effects of different levels of NaCl used in the diet of cultivated Huso huso juveniles based on gene expression of Insulin-like Growth Factor (IGF), IGF mRNA in the liver and muscle. Totally 480 specimen beluga juvenile by the average weight of 173.8±0.49 g stocked in 12 tanks and reared for 12 weeks. The NaCl added in 4 levels and with three replicates of 0(control), 3, 6 and 9 percent to the basic diet. After 12 weeks total RNA extracted from the16 liver and muscle which were sampled from two replicates of treatments and evaluated by electrophoresis. β2m-qPCR primer was used as gene reference. The size of the product obtained from primers and the specific degree of action of primers was confirmed using agarose gel (1.5%) and the sequencing of the genes.According to the results, significant changes in IGF mRNA expression observed in the treatments and control group (P<0.05). The data of IGF gene expressions showed that the highest levels observed in the control group and treatment 3% respectively. Moreover, in the tissue of white muscle, IGF mRNA gene expression showed highest gene expression in the control group (6.4) and lowest expression were in treatment 3% (0.7) and treatment 6% (0.8). Also, growth indices results including body weight, Specific Growth Rate(SGR), Body Weight Index(BWI), Hepatosomatic Index(his) and Average Daily Growth(ADG) significantly were increased in all treatments, with significant differences among treatments and the control group (P<0.05). The SGR in the control group increased from 1.41 to 1.58 in treatments 3% and 6% and the BWI increased from 68.88 in the control group to 98.28 in treatment 6%. HSI increased from 3.64 g in the control group to 4.37 g in treatment two. FCR showed a significant difference in the control group (1.27) and 1.14 in 3% and 9%, respectively. Statistical analysis of FCR, SGR and IGF mRNA gene expression showed better growth indices in fish fed by a diet containing NaCl.

Cyanobacteria (blue-green algae) are a unique group of photosynthetic bacteria amongst the oldest forms of life, which widespread in aquatic environments including freshwater lakes, rivers and reservoirs. Furthermore, they have ability to produce a wide range of secondary metabolites with toxic property for aquatic animals, as well as human beings. Considering the importance of cyanobacteria in public health, the introduction of sensitive and reliable methods for their detection is the main aim of this study. In the present study, 30 water samples were collected from six locations of the Kor River, Iran. The samples were analyzed for the prevalence of cyanobacterial species using conventional culture methods and morphological tests. Then, molecular identification of the isolates was performed by the comparative evaluation of three sets of primers (CYA106/CYA781; CYA781/CYA359; and PCα/PCβ). Furthermore, their abilities to produce cyanobacterial toxins including microcystin and nodularin synthetase enzyme complexes were investigated by using polymerase chain reaction method. The results obtained from this study indicated that two isolates were identified as Cyanobacterium aponinum and Phormidium sp. none of the isolates had ability to produce selected toxins. In addition, the results indicated that the selected pair primers were proper for detection of the isolates. Hence, due to importance of cyanobacterial isolation from water samples and their effect on human health, periodic studies in different water resources and regions seem necessary. Furthermore, among the selected primers, CYA106/CYA781 could be a proper primer pair for detection of cyanobacterial isolates.

Inclusion of dietary herbal supplements in aquafeed can be considered as a growth promoter and enhancer of immunity system in preventing various fish infections. Therefore, this experiment was conducted to evaluate the effects of different levels of purslane (Portulaca oleracea) extract (POE) on growth performance, hematological indices and immune responses of rainbow trout fry. The fries with initial weight of 3.3±0.1g were divided into four groups with feeding diets supplemented containing 0% (control, T0), 0.5% (T1), 1% (T2), 1.5% (T3) and 2% (T4) of POE for 56 days. After eight weeks of feeding trail, enriched POE diets significantly increased red blood cell count, white blood cell count, hematocrit, hemoglobin concentration, mean corpuscular hemoglobin (MCHC), neutrophil and monocyte percentages, especially in T3 group compared to the control group (p<0.05). Although no significant differences were observed between eosinophil percentage and MCHC, but lymphocyte percentage decreased significantly (p<0.05). Also supplemented diets with POE significantly increased immune parameters including total immunoglobulin (Ig), IgM, complementary activity, total protein and lysozyme activity in all experimental groups, especially in T3 (1.5% POE) compared with the control group (p<0.05). This study demonstrates POE as a potential immunostimulant to stimulate and improve immune system of rainbow trout fry.

A climate driven changes in the coastal region of Bangladesh is saltwater intrusion in freshwater, which may directly affect the fishery production as well as economy and food security. Investigation on effect of different concentration of salinities (0, 5, 10, and 15ppt) on hemato-biochemical parameters, behavioral responses and gill morphology at certain time intervals (1, 6, 12, 24, 36, 48, and 72 h) were observed in a spotted snakehead, Channa punctata. In the present study the biochemical parameter and glucose exposed a significant (p<0.05) changes associated with different exposures at different time intervals. The hematological data of C. punctata revealed significant (p<0.05) decrease in red blood cell (RBC) count. The hemoglobin level in every treatment was lower till 24 h and then it increased up to 48 h but white blood cell (WBC) count, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) showed significant (p<0.05) increase compared to the control.  Increase and decrease of hematological indices expressed that fish exposure to different salinities were under stress. Unusual behavioral responses with various pathological signs in gills were also perceived. The results specified that the intrusion of saline water into the freshwater have deleterious effects on the hemato-biochemical parameters including gill morphology and behavior. So, the intrusion of saline water should be controlled to avert the losses. 

Feeding ecology of Acrossocheilus yunnanensis, a dominant fish in the headwaters of the Chishui River, a tributary of the upper Yangtze River, was studied using the analysis of gut contents. From March 2015 to January 2016, a total of 543 individuals were collected and analyzed. The results showed that A. yunnanensis was an omnivorous fish mainly feeding on chlorophytes, diatoms, and aquatic insects. The trophic level was 2.69±0.62 (mean±SD), signifying A. yunnanensis as a primary or secondary predator. Dietary shifts were found among different ontogenetic stages and seasons. Specifically, young individuals fed primarily on aquatic insects and diatoms, whereas older fish fed mainly on chlorophytes. In spring, the preferred food item was aquatic insects and in other seasons, chlorophytes became the predominant prey. Diet composition showed no differences among individuals of different sex and diel periods. The feeding intensity of A. yunnanensis was not affected by diel periods, suggesting this species feeds continuously. However, its feeding intensity was significantly influenced by seasons. Pairwise comparison found that the feeding intensity was higher in spring and autumn than that in summer and winter, with minimum food intake in winter and maximum in spring. Analysis on Amundsen graph and niche breadth index indicated that A. yunnanensis might pursue an opportunistic and moderately generalized feeding strategy, which could explain why it has become the dominant fish species in our study area.

An analysis of sexual pattern, spawning ecology, and size at sexual maturity in two queenfishes (Talang queenfish, Scomberoides commersonnianus and needlescaled queenfish, S. tol) was made. Fish samples were collected monthly by gillnet and trawls from the northern Arabian Sea coast of Pakistan from July 2013 to June 2014. The gonad maturity was categorized in six developmental stages based on visual analysis (colour, morphology) and histological screening of the gonads. The males of Talang queenfish dominated the population with a ratio of 1:0.4 (♂ to ♀) whereas females were higher (1:1.6) in needlescaled queenfish population. Talang queenfish was reproductively active during summer with a peak in June and winter spawning season, which appeared from November to February. Needlescaled queenfish is repeatedly spawner, appeared to be in spawning in the summer and fall. Estimated size-at-sexual-maturity for Talang and needlescaled queenfish suggests that the minimum legal length (MLL) should not be set lower than 35, 38 cm TL respectively. This conservative MLL, equal to or more than a length at functional maturity of both queenfish species would safeguard immature individuals until they reach a size at which they can contribute to the reproductive capacity of the populations in the northern Arabian Sea coast.

Abundance, community composition, diversity and density of zooplankton were analysed in Tercan, Kuzgun and Demirdöven Dam Lakes between January-December 2014 seasonally. During the study period a total of 38 zooplankton species have been observed, with 25 species of Rotifera, and 8 species of Cladocera and 5 species of Copepoda. 28 species in Tercan Dam Lake, 26 species in Kuzgun Dam Lake and 27 species in Demirdöven Dam Lake were identified. Rotifers were the dominant group among zooplankton community, constituting 65.7% of the total zooplankton population. The highest (H′=2.75) and the lowest (H′=0.68) Shannon diversity index values were recorded at Demirdöven Dam Lake. And also the highest value of Simpson index (D=11.63) was recorded in Demirdöven Dam Lake indicating low species dominance in spring. Pielou evenness (J) index value was showed its maximum value with 0.98 indicating uniformity in zooplankton community.

This paper presents the first record of Metalia persica, (Mortensen, 1940) from the Gulf of Oman. The new record extends geographical distribution range of this spatangoid species to the eastward. Morphological and ecological notes as well as the distribution range of M. persica are also provided.

Bioaccumulation and distribution of heavy metal (Se, As and Pb) in muscle, gill and hepatopancreas of blue crab Portunus pelagicus from Bushehr coast, north part of the Persian Gulf, were investigated. Analyses of samples were by a GBC-932 AA Atomic Absorption Spectrophotometer. The average concentrations of Se, Pb and As in all tissues of crab were 0.485, 1.89 and 0.615 µg g-1 respectively. The linear regression analysis showed there were a positive correlation between heavy metal levels and crab size. Also, there was a direct relationship between heavy metals levels in tissues crabs with feeding habitat. Comparison between male and female indicated that the average of heavy metal concentrations in female crabs were higher than those in the male crab, because female crabs feed on benthic animal that are close to bottom sediment and receives more sediment associated metals.

Chabahar Bay is located in southeastern coast of Iran and the northern part of the Oman Sea in the geographic area of 25°22́ 47˝N  and 60°39́  90˝E. This Bay with having a variety of coverings, such as, muddy, stone, sandy and rocky, has provided possibility of life for different taxa, such as, shellfish, mollusks, echinoderm ( Ghanbarifardi and Malek, 2009; Yazdani et al., 2009; Sadeghi and Loghmani, 2010; Khaleghi and Owfi, 2011; Fazeli et al., 2013; Attaran et al., 2014). Ophiuroids are relatively small echinoderms that all live in marine habitats, such as, sandy, rocky, stony, muddy, on sponge and corals (Barnes et al., 2001). Ophiuroids with above 2,000 species are a big group of echinodermata distributed in all marine environments from polar to the equator, and from the intertidal to subtidal zone (Pawson, 2007). In the present study, ophiuroids species are identified based on their morphological features and introduced from Chabahar bay.