فصلنامه شیلات
سال هفتادم شماره 1 (بهار 1396)

This study was aimed to review the status and distribution of the members of Cichlidae family in the Iranian inland waters along with first report of Nile tilapia, Oreochromis niloticu from Iran. After sampling, examination of museum’s specimens and review of articles on the members of this family, presence of six species in four genus, including Amatitlania nigrofasciata (Namak Lake and Hormozgan basins), Coptodon zillii (Persian Gulf basin), Iranocichla hormuzensis (Hormozgan basins), I. persa (Makran basin), Oreochromis aureus (Persian Gulf basin) and O. niloticus (Persian Gulf basin) were confirmed in the Iranian inland water. The results also revealed the extensions of their distribution range. Two species out of six reported species are endemic and others exotic. Although most of the exotic species have no remarkable effect on their living ecosystem, but some of them can have negative environmental and economic impacts. Therefore, it is necessary to fulfil a comprehensive evaluation of their impacts on the inhabiting environments to protection of native fishes as well as sustainable exploitation.

The present study aimed to investigate the effects of different concentrations of effluent from municipal wastewater treatment plants on blood biochemical factors, cortisol level of blood, liver and gill tissue of silver carp (Hypophthalmichthys molitrix) in a culture system. The experiment was conducted as five treatments, 0% (control, 1), 25% (2) 50% (3), 75 % (4) and 100% (5) waste water concentrations in triplicates. During two months as an experimental period, the fish were fed with a commercial pellet (Fradaneh Factory product) and the rate of mortality was recorded .the rates of mortality were 8%, 12%, 12, 20% and 16% in treatments 1, 2, 3, 4 and 5, respectively. According to the results, with increasing in concentration of treated wastewater, cortisol levels of blood increased significantly (P

In this study 18 Capoeta aculeata from Qanats in Namak basin, Naieen, Ardestan and rivers in Karun basin were analyzed using Cytochrome Oxidase subunit I (COI) sequences. Totally 5 haplotypes were retrieved. The observed haplotypes in Qanats of Ardestan and Namak basin in Tehran province were exactly the same and this similarity can be a sign of common origin of them. The haplotypes observed in Qanats of Naieen region were different from haplotypes observed in other regions. The haplotypes observed in Karun and Namak basins were closely related. This close affinity can be indication of a past possible connection between the two basins. The K2P divergence among the haplotypes in the studied regions varied between 0.2-0.7 percent. The results showed that Capoeta group is a monophyletic group with close affinity to the species of the genus Luciobarbus compared to other genera analyzed here. The divergence of Capoeta aculeata from C. capoeta seems to be occurred about 4.24-5.1 MYA.

In the present study, effect of acute concentrations of mutagenic butachlor herbicide (0.0, 0.4, 0.5 and 1 mg/l) which are named as groups A, B, C and D with durations of exposure of 48, 72 and 96 hours is investigated on some blood parameters (RBC, Hct, WBC, Hb, MCH, MCHC, PCV, MCV, TP, ALP, AST and ALT) in Rainbow trout. Based on two-way ANOVA statistical analysis, concentration, duration of exposure and the interaction of these two variables had significant effects (P

This study was conducted to evaluate the antioxidant and antimicrobial effects of Oregano (Origanum Vulgare L.) essential oilon surimi preservation during freeze keeping. After manually production of surimi, half of it was mixed with cryoprotectant and used as a control and the other half was mixed with 0.5% of oregano essential oil (w/v), packed in plastics and then stored at -18°C for 0, 1, 3 and 6 month, respectively. The results showed that there was no significant difference between treatments in the case of ash (%) however; protein and fat (%) were significantly lower in control (surimi without additive) than those supplemented with oregano. TBA, TVN and peroxides significantly decreased in oregano treated surimi in all months compared to control. After 0, 1 and 3 month, total psychrophilic (TPC) and pseudomonas bacteria were similar in both treatments. However, total amount of bacteria significantly decreased in treated surimi at the end of 6 month storage as compared to control. The results of color indexes showed that, there was no difference in redness index in all periods; however whiteness and yellowness indexes were significant after 1 and 6 month and lighting index in treated surimi after 1, 3 and 6 month storage. Generally, it can be concluded that, addition of oregano essential oil at 0.5% w/v can improve antimicrobial and antioxidant properties and decrease microbial and oxidative spoilage in surimi.

In this study, effects of aloe vera on growth performance, Hematology and serum biochemical indices and the resistance to Saprolegnia parasitica were studied in rainbow trout for 8 weeks. Aloe vera powder at levels of 0, 5, 10 and 15 g/kg were added to a basal diet. At the end of trial period, the fish were exposed to the fungus S. parasitica. The results showed that all treatments fed with aloe vera-included diets showed significant increases in weight gain, specific growth rate and reduced feed efficiency compared to the control. Also fish treated with aloe vera showed significant increases in hematology and serum parameters in comparison with control. However, significant reduction in mortality was observed in the treated fish with 15 g/kg diet of aloe vera compared to the other treatments and the control following challenging with S. parasitica, but 5 g/kg diet of aloe vera survival rate increased significantly compared with control. According to the results, the use of aloe vera powder, especially at a level of 5 g/kg in rainbow trout diet is recommended in order to improve growth and immunity parameters as well as boosting fish resistance against S. parasitica contamination.

Fish oil is one of the most valuable marine products. It is used as unrefined oil in animal, poultry and aquatic organisms feed. Also, fish oil has high amount of Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA) and can be used as a food supplement by human. The purpose of this project was oil extraction by supercritical fluid extraction (SFE) and wet pressing (WP) methods from by-products of canned tuna factories. Yield (%) and quality of obtained oil were studied (with focus on human consumption). For this aim, extracted oil from raw materials were evaluated to determine different indices, formed compounds as results of lipid peroxidation and pollutant content based on toxic metals. Yield (%) and moisture content of oils did not show significant different in both methods. Some of volatile components such as aldehydes were detected in WP method and the number of detected alkanes in WP treatment was higher than SFE. On the contrary, acetic acid as a non-lipid acid was detected in SFE treatment. DMA as responsible for the highest level of fishy odor was detected in SFE and WP. Neutral lipids (such as wax esters, TAG, FFA and CHOL) and acidity value did not show significant different between treatments. The amount of DHA in fatty acids profile was higher in SFE methods in comparison with WP. Also, the amounts of toxic metals such as Hg, As, Cd and Pb in SFE treatment were significantly lower than WP. Thus, the results of this study showed tuna by-products have appropriate potential to extract oil for human consumption and SFE is a good process to extract it.

Extensive production of zinc oxide nanoparticle in science and industry can increases the risk of releasing this material into the environment in near future. Nanoparticles may cause a lot of damage at different levels after being released into aquatic ecosystems due to accumulation in the body and transfer to higher levels of food chains. To find effects of zinc oxide nanoparticles on the gill tissue in rainbow trout, 80 fish were randomly used with an average weight of 42.88 g in four plastic tanks (volume: 90 liters) and exposed to four different treatments with three replicates. The treatments were control (without ZnO), three treatments with concentrations of 0.025, 0.05 and 0.075 mg L‑1 zinc oxide nanoparticles (with an average size of 40-30 nm). Tissue samples were collected in four stages. The tissues were dewatered, placed in paraffin and cut using a microtome and finally stained with hematoxylin-eosin. To examine significant differences among treatments, a linear model based on rank data was used, with severe negative symptoms got the greater rank and data was analyzed using Rfit package in R. The observed changes indicated that zinc oxide nanoparticles may have significant effects on the gill tissue, therefore, the gill can be used as a biomarkers to assess impacts of environmental pollutants.

This study was aimed to evaluate the development of the digestive system in common carp (Cyprinus carpio) var. Sazan, as a commercially valuable species of the Caspian Sea from hatching up to 55 days post hatching (DPH) based on parifinized histological technique and hematoxylin-eosin staining method. The results showed that moth opening, appearance of pancreas on 2 DPH, epithelial layers of the buccal cavity and esophagus along with their Goblet cells on 3 DPH, rectum on 8 DPH and coiled intestine on 12-13 DPH were occurred. In addition, according to morphological and histological characteristics, the early development of the digestive system in common carp var. Sazan can be divided into three main stages: (1) from hatching up to 3 DPH that is coincide with mouth opening and is readiness of the digestive tract to receive food, (2) up to 8 DPH, is a transitional stage from endogenous toward exogenous feeding that digestive system of larvae is developed in terms of structure and function to receive, digest and absorb of food before the absorption of yolk sac, and (3) third stage from 9 DPH that the pancreas is became functional as main characteristic of this stage, and an essential diagnosis feature of transforming the larvae to young fish. Development of the digestive system in common carp var. Sazan during early stages was similar to other bony fishes with differences in oncogenic and function times.

The objective of this study was to investigate the genetic diversity within and between Iranian, French and Danish rainbow trout, Oncorhynchus mykiss. Mitochondrial DNA (mtDNA) of 135 samples (45per each breed), isolated by phenol-chloroform extraction method, was studied by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Fragments that included 986 bp of D-loop and 974 bp of Cyt b of mtDNA were amplified and investigated using different restriction enzymes. None of samples showed variation for restriction enzymes in D-loop. Using restriction enzymes, on gel electrophoresis, four different haplotypes were detected in Cyt b among which two breed specific haplotypes were observed in Danish population. AABBAB haplotypes had the most frequency with 61 events. UPGMA dendrogram based on cytochrome b gene showed that the Iranian population make cluster with French population rather than the Danish population. The genetic distance was 0.0008 between Iranian and French populations and 0.198 between both Iranian and Danish and French and Danish populations.