فصلنامه شیلات
سال شصت و هفتم شماره 2 (تابستان 1393)

Annually، the large volumes of paper mill effluent to the environment in Iran. The major pulp and paper mill contain a large amount of alcohols and fatty acids and resin acids. Such materials stimulate vitellogenin production and suggested to be an estrogen mimic which cause sterility، sex reversal، yolk advance of replication and disruption of hormone cycles in fishes. Recently، vitellogenin gene quantification is considered as an efficient biomarker for the detection of estrogenic wastewater. Therefore، in this study the real time quantification of vitellogenin gene was used to evaluate the impact of pulp and paper mill on rainbow trout. After LC50 detection، the fish was exposed to 200 and 500 ppm (0. 1 and 0. 25 LC50، respectively) of the pulp and paper mill obtained from Mazandaran and Pars ahvaz company- Iran for 6 and 14 days and compared with control. To evaluate vitellogenin gene expression، the liver was taken from fish on days 0، 6 and 14. RNA was extracted from the tissue and evaluated on 1% agarose gel and Nanodrap. After cDNA synthesis، the samples were subjected to Real time PCR machine and gene expression analysis was performed using Sybr Green method. The results of this study indicated that the 500 ppm treatment stimulate vitellogenin gene expression at both 6th and 14th days exposure، when comparing with control (P< 0. 05). After 6 day exposure، the fish treated with 200 ppm pulp and paper mill did not show significant difference in respect to vitellogenin gene expression، where comparing with control while significant increase (P< 0. 05) was observed after 14th day. This suggest pulp and paper mill influent on vitellogenin gene expression and can be used as a biomarker for such wastewater.

Aphanius ginaonis is exclusive to the Geno hot spring, located in the Hormozgan province. In this paper some biological aspects of Aphanius ginaonis and contents of its digestive tract and its relation with cyanobacteria (blue-green algae) in the Geno hot spring was examined. Sampling was conducted monthly, samples were fixed in 5% formalin immediately after fishing and transferred to the Ichthyology lab for next steps. In this study the biological characters such as total length, standard length, length of gut, total weight and weight of gut where measured and the sex was determined. Then the digestive tract was opened and its contents were investigated. The contents of each part of digestive tract were examined separately, which were mostly contain cyanobacteria. The digestive tract cyanobacteria were identified by using the valid identification key and determined that Spirulina subsalsa is the most common cyanobacteria in digestive tract in A.ginaonis. It seems that this fish species diet is mostly herbivorous but sometimes also feeds on aquatic insect larvae. As regards in habitat of Geno tooth-carp, 32 species of cyanobacteria have been identified, on the other hand various species of Spirulina are rich of protein, it seems that A.ginaonis are able to identificate and select among various species of cyanobacteria.

Vitellogenin (Vtg) is a glycophospholipoprotein precursor of egg yolk which circulating levels of this protein in male and juvenile fish provide a sensitive indication of exposure to endocrine disruptor chemicals. The objectives of the present study were identification and purification of beluga (Huso huso) Vtg using Vtg selective precipitation (EDTA-Mg+2) and excision of Vtg band from reducing gel preparative. In this study, required plasma samples were collected from vitellogenic beluga and Vtg was identified using the specific characteristics of this protein (range of molecular weight, specificity for female, estrogen inducibility, precipitation in the presence of EDTA as well as specific reactivity of putative beluga Vtg with antibodies to beluga Vtg). Vtg highly purified by combination of Vtg selective precipitation and gel preparative. With SDS-PAGE under reducing conditions, beluga Vtg appeared as a major band of ~200 KDa. These data suggest that vitellogenin selective precipitation followed by gel preparative is an efficient procedure for the characterization and purification of beluga Vtg.

In this study the feasibility of producing a good quality fish protein powder from mince and surimi of common carp (Cyprinus carpio) and its application in formulation of cookie was evaluated. The chemical composition, color, texture and sensory evaluation of prepared cookies were determined. By replacement of fish protein powder with wheat flour significantly (P<0.05) enhanced the protein content of prepared cookies. The highest L* value (59.46) was allocated to the treatment containing 15% surimi protein powder and the lowest (53.03) was belong to the one prepared with 15% mince protein powder. The hardness of cookies with 5%, 10% and 15% surimi protein powder (SPP) was recorded at 2.31, 2.58 and 3.80 N, respectively; whereas it was 2.74, 3.09 and 3.11 N for treatments containing 5%, 10% and 15% mince protein powder (MPP), respectively. In terms of hardness, there was no significant difference (p>0.05) among the treatments. The same trend was observed in terms of deformation of treatments. According to the panelists, the score of overall liking of the best toward the worst treatments were as control (8.03), 5% SPP (7.11), 10% SPP (6.21), 5% MPP (5.08), 15% SPP (4.92), 10% MPP (3.71) and 15% MPP (3.5), respectively.

This study was conducted to compare the morphometric and meristic characteristics of up- and downstream Capoeta capoeta populations in Manjil and Tarik dams at three part of Sefidroud River. A total of 100 individuals of Capoeta capoeta including 40, 27 and 33 specimens from upstream and downstream Manjil dam and downstream Tarik dam, respectively were caught by electrofishing. Thirty six morphometric and 12 meristic characteristics were examined. The extracted data were analysed after data standardization using principal components analysis (PCA) and canonical variate analysis (CVA). CVA revealed that these three populations were distinct from each other in morphometric characters. PCA showed that these three populations are distinct from each other in morphometric characteristics (making 3 principal factors). We conclude that different habitat conditions caused by Manjil and Tarik dams may be led to different meristic and morphometric charactristics.

The main objective of the present study was investigation on influences of different brackish water sources on freshwater prawn larval quality and developmental indices. For this study, along a larval period, four brackish water treatments with 12 PPT salinity including diluted marine water, brackish water from marine crystalline salt, brackish water with compounds of New formula and brackish water from municipal drinking water and kitchen salt were prepared; Then larval quality and developmental indices such as larval Stage index (LSI), Larval Condition Index (LCI), larvae dry weight, larval period long, tolerance to formalin stress (LC50-24 h) and survival rate were compared among these different treatments. The findings indicated that the balance of calcium and magnesium concentrations in brackish water is very important on growth, quality and larval development of freshwater shrimp larvae. The concentration of potassium ion between the Mysis and Zoa stages is very important on the larval development so that significant difference for LSI at 10 days post hatch in brackish water from New artificial formula is due to appropriate potassium concentration in it. Also the results showed that brackish water prepared from dilution of marine water is the best case for freshwater prawn hatchery and the brackish water from municipal drinking water and kitchen salt is not suitable for the hatchery; so brackish water prepared from dilution of marine water is suggested for the freshwater prawn larval period in hatcheries.

Polycyclic aromatic hydrocarbons (PAHs) are known as persistent pollutants in marine ecosystem which, originate from several sources and cause many problems for both aquatic organisms and human. The study of PAHs compounds ratio in bivalves can help to determine their source and rout of input in to the sea and such information can be used in fisheries and environmental management. Since oil related industries are well developed in Bushehr coastal waters this area is supposed to be impacted by PAHs. This study was carried out to determine the concentration of PAHs and their source in ark clams (Barbatia helblingii) along Bushehr shoreline. Samples of ark clams (Barbatia helblingii) were collected from five different stations. 30 numbers of clams in same size (mean: 35mm) were collected from each station. They were dissected and their soft tissues were digested in methanol. PAHs content of the samples was extracted by hexane and analyzed using HPLC. Result showed that tPAHs concentration in clams ranged from 125.5 to 634.7 ng g-1(dw). Significant difference was observed between tPAHs concentration in clams belonged to different stations (P<0.05). The maximum and the minimum concentrations of PAHs were measured in clams collected from stations Rafael and Abshirinkon respectively. Results obtained from some relative ratios of single PAHs compounds indicated that Bushsher shore line receives PAHs from both pyrolytic and petrogenic origins. Due to low PAHs concentration and bioavailability in station Abshirinkon, It Appears that this site is suitable place to establish aquaculture fields. The mean concentration of tPAHs in B.helblingii was 421.6 ng g-1which was notably higher than what reported form some other bivalve species from other parts of the world, which is indication of high bioavailability of PAHs. Due to adverse effects of PAHs on human and aquatic life, study of PAHs in edible fishes is necessary.

To identify situational influences parameters on fish home consumer’s behavior was designed of questionnaire in Tehran. After the Reliability and viability evaluation of questionnaire. it was prepared and filled randomly for 295 of households of different localities of Tehran with considering the proportion of population in each localities. The degree of importance of effective parameters and their priority were calculated by Fridman test, and the effective parameters with priority was done among all groups of fish consumers. The results showed that, Hygiene Place, smell, ambient ventilation, presentation, cleanliness and clothing seller and their behavior, Crowded store and Picking Method are the most important situational influences purchasing and consumption factors totally of Tehranish households, Curiosity was the main motivation for buying first-order. While buyers are most interested in buying fish from the fish store.

The induced stress by pollutants such as heavy metal, is caused cellular responses leading to ultrastructural changes. The ultrastructural alternations of epithelial cells in the bladder of crayfish (Astacus leptodactylus) to study the effect of mercuric chloride treatments were conducted. Eighty specimen of crayfish were collected from the Anzali wetland and every 20 of them were divided into four treatments with concentration of 0, 5, 15 and 20 ppb of mercury chloride. After one week of exposure period, their green gland were removed and fixed into glutaraldehyde for TEM study. There was no losses during experiment in 0 and 5 ppb treatments, whereas 20% and 100% of death were recorded in 15 and 20 treatments, respectively. Results did not show any ultrastructural alternation in the epithelial cells of bladder at 0 dose. In 5 ppb treatment, observed ultrastructural alternations were the complexity of basal membrane cells, swelling and deformation mitochondria and the significant increase in the number and size of vacuoles. In 15 ppb dose in addition to mentioned alterations, degeneration of mitochondrial crystals, increasing excessive deformity of vacuoles and in general, necrosis of cells were observed. The results showed that the green gland of crayfish could be the main site of detoxification and removal of the entered mercury in hemolymph. Due to its high accumulation in bladder can cause ultrastructural alterations and damages by disturbing mechanism of waste discharging and specially osmoregulation would cause death in this aquatic organism.

Six loci microsatellites IC228، IC434، IC720، Bbar3، Bbar7 و Bbar8 were used to determine genetic variability and population structure at Berim and Kheyrabad rivers. Sixty samples (30 individuals for each river) were used. Total 125 alleles were detected with an average 10. 4 alleles per locus. The highest and lowest observed number of alleles was 17 and 6 for Berim population, respectively. The average observed (Ho) and expected heterozygosity (He) was 0. 467 and 0. 843, respectively. 10 Loci of our study showed significant deviation from Hardy-Weinberg equilibrium. Results Fst (0. 036) and Rst (0. 341) values showed low genetic differentiation among the populations; also, AMOVA analysis indicated only 3% genetic diversity between populations. Protection and restoration of habitats can help to increase the population size and decrease risk of vulnerability of the species in the future.

Nowadays, fish has been considered as one of the most important natural resources to provide nutritional requirements and support human health worldwide. On the other hand, seafood consumption has been reported as an important route of human exposure to a variety of chemical contaminants including heavy metals such as mercury. In this study total mercury levels were measured in 30 canned Yellowfin tuna (Thunnus albacares) from Famyla company product and then were compared with international standards. Weekly limit consumption based on the limit provided by the World Health Organization was provided. Wet digestion method was used and the samples were analyzed by ICP-OES. The results showed that the average concentration of mercury in this product was 0.126 μg/g of wet weight which was less than the allowable amount for human consumption determined by the international organizations such as WHO, FAO, USEPA, FDA, EC and MAFF. In this study, average available methyl mercury in canned Yellowfin tuna was 0.126 μg/g of wet weight which is less than the safety level of methyl mercury in fish. Risk index (HQ) was below 1 (0.54) therefore, the consumption of this product is not a serious threat to the consumer’s health and according to USEPA and JECFA standards, consumption of 2-3 meals of canned Yellowfin tuna per week is allowed.

In this study antioxidative property of Cutlassfish (Trichiurus lepturus) protein hydrolysate produced in 7 hours hydrolysing by Protamex from fish viscera and meat has been investigated. Maximum nitrogen recovery and degree of hydrolysis was 89±6%, 65±3%, and 93±8%, 79±7% for viscera and meat hydrolysate, respectively. Maximum DPPH free radical scavenging activity was 88±6% and 90% for viscera and meat hydrolysate, respectively (P<0.05). Maximum absorption of 700 nm wave length was 0.99±0.05 and 0.99±0.04 in 7th hour for viscera and meat hydrolysate, respectively. Maximum metal chelating activity was 80±4% and 88±3% for viscera and meat hydrolysate, respectively. Fish oil in water emulsion system showed antioxidative capacity until 72 hours after starting the reaction (P<0.05). All reactions didn’t show any differences in compare to standards unless chelating activity. Glutamic acid and aspartic acid was in maximum range. In conclusion, viscera and meat protein hydrolysate of Cutlassfish have good antioxidative properties and could be used as food additives after clinical approve.