12 research outputs found

    Effects of hydrogen peroxide on fungal disinfection, hatch rate and larval deformities of rainbow trout (Oncorhynchus mykiss)

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    The hydrogen peroxide in concentrations of 500, 750 and 1000 mu l/l, malachite green with usual concentration (1.5mg/l) and natural control treatments were examined to evaluate the antifungal effects of the chemicals on Rainbow Trout eggs. Hydrogen peroxide and malachite green treatments were performed after 48 hours after fertilization in every other day, until 4 days before hatch, each time for 15 minutes. During experiments, water parameters were measured which were 8.05±0.55mg/l for dissolved oxygen, 8.8±2.2 ° C for temperature, 7.9±0.05 for pH, 132±20mg/l for total hardness, and E.C was 336±24 mu s/cm. The fungal infection was minimal in malachite green treatment and was significantly different with other treatments (P>0.05). No significant difference in deformities caused by the treatments were observed (P>0.05)

    Induction of tetraploidy in rainbow trout (Oncorhynchus mykiss) by heat shock

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    This study has been conducted for determination of optimum time and duration of thermal shock on tetraploidy induction in Rainbow trout. This study was carried out by induction of 28°C thermal shock in different times after fertilization (49.5, 54.0, 58.5, 63.0, 67.5, 72.0, 76.5 and 81,0°C/hour and different duration (8, 10 and 12 min). Nuclear erythrocytes, cellular area and volume measurement were determined among blood smears of fingerling and statistic analysis showed that, induction of tetraploidy was conducted between 0-75% on various treatment, but highest tetraploidy yield (8.4%) was achieved by thermal shock on 28°C within 12 minutes, 74 degree-hour after fertilization. Moreover, tetra ploidy diagnostic was also approved by determination of nucleolus number in fishes. In this respect tetraploid and diploid fishes have 3-4 and 1-2 nucleolus, respectively

    Morphometrics studies of Mahisefid (Rutilus frisii kutum, Kamensky, 1901) from selected rivers in the southern Caspian Sea

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    Mahisefid, Rutilus frisii kutum , is a cyprinid fish which is distributed from Turkmenistan to Azerbaijan along the Caspian Sea. It is one of the economically important fish in the region. As part of the Iranian Fisheries Company’s policy to improve the stocks of this species, every year, fingerling of Mahisefid are released into the southern basin of the Caspian Sea. The main objective of this study was to determine populations in different of rivers. In total, 387 fish were collected from four rivers, including Lemir, Sefidrood, Shirrood and Tajan, where this fish migrates for spawning, in spring 2005. Thirteen conventional morphometric factors, 13 ratio and 12 Truss morphometrics were measured and calculated in this study. Conventional and Truss morphometric data were analyzed using two-way ANOVA Principal Component Analysis and discriminant. Average of coefficient of variation (CV%) of morphometric in males was 14.95, 10.28, 17.47 and 16.56 and in females was 21.35, 19.74, 18.25, and 19.74 in Lemir, Sefidrood, Shirrood and Tajan River, respectively, showing that all morphometric characters were significantly different (P<0.05) among four sampling sites (populations). The first component of morphometrics 44.32% in males and 68.94% in females were positive, indicating that the conventional morphometric was good descriptor of the body shape variation among the populations, especially in females. The total cumulative variances were 76.6% and 87.8% in males and females, respectively, suggesting that this can be considered as a useful discriminator. The total cumulative variances were 64.27% and 64.21% in males and females, respectively. The first component of truss was 87.7% and 81.3% of the total variance, in males and females, respectively. The results of the present study suggest that each sampling site represents independent population in each river

    Morphometrics Studies of Mahisefid (Rutilus frisii kutum, Kamensky, 1901) from Selected Rivers in the Southern Caspian Sea

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    Mahisefid, Rutilus frisii kutum , is a cyprinid fish which is distributed from Turkmenistan to Azerbaijan along the Caspian Sea. It is one of the economically important fish in the region. As part of the Iranian Fisheries Company’s policy to improve the stocks of this species, every year, fingerling of Mahisefid are released into the southern basin of the Caspian Sea. The main objective of this study was to determine populations in different of rivers. In total, 387 fish were collected from four rivers, including Lemir, Sefidrood, Shirrood and Tajan, where this fish migrates for spawning, in spring 2005. Thirteen conventional morphometric factors, 13 ratio and 12 Truss morphometrics were measured and calculated in this study. Conventional and Truss morphometric data were analyzed using two-way ANOVA Principal Component Analysis and discriminant. Average of coefficient of variation (CV%) of morphometric in males was 14.95, 10.28, 17.47 and 16.56 and in females was 21.35, 19.74, 18.25, and 19.74 in Lemir, Sefidrood, Shirrood and Tajan River, respectively, showing that all morphometric characters were significantly different (P<0.05) among four sampling sites (populations). The first component of morphometrics 44.32% in males and 68.94% in females were positive, indicating that the conventional morphometric was good descriptor of the body shape variation among the populations, especially in females. The total cumulative variances were 76.6% and 87.8% in males and females, respectively, suggesting that this can be considered as a useful discriminator. The total cumulative variances were 64.27% and 64.21% in males and females, respectively. The first component of truss was 87.7% and 81.3% of the total variance, in males and females, respectively. The results of the present study suggest that each sampling site represents independent population in each river

    A Study on necessary infrastructures used for breeding trout in Yasoj region

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    Rainbow trout is the main cultural species of coldwater fishes in iran. Often, aquaculturists intend to breeding in order to production of lines with higher growth rate potential and disease resistant. Nevertheless in the country, no trout breeding programs, has been performed yet and most of the farms focused on the cultivation of the first(unbred) race. While European countries progressed in trout breeding techniques and production lines with higher growth through genetic manipulation (chromosomal number and type changes of fish) and/or selection and their fish products derived from this technology, including eyed eggs and so on have sold to other regions of the world(eg: Iran). In this study, some biological parameters including survival, growth, feed conversion ratio (FCR.) and chromosomal number of two juvenile groups from imported( group 1) and native(group 2) eyed fish eggs were compared. For chromosomal investigation, blood smear test and flow cytometry were performed. sults showed a significant difference (P≤5%) in growth rate of native fishes and French group Native fish feed conversion ratio (0.9) was significantly difference (P≤5%) from that of French fishes (1.15). Chromosomal analysis showed no difference in chromosome number in treatments and two fish groups were 2n chromosome. Based on the results, the fishes of group 1 had faster grow potential and gain weight in less time than that of group 2 and this has been achieved to go through the process of selection and feminization without any change in number of ploidy. Whereas the ability of native fishes in food efficiency ( lower FCR.) was better. However, the reduction of rearing period is the benefit and preference of cultivation of imported or origionally foreign

    Bester (beluga ♀ × starlet ♂) production and comparing their growth with beluga in Iran

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    Aquaculture for human consuming species is being considered as the first substitution of catching aquatic species due to increase of human population and decrease of wild aquatic stocks. In this study, the hybrid sturgeon Bester (female beluga x male sterlet) was produced for the first time in Iran. Sperm of 1.35 kg male Acipenser ruthenus was used to fertilize the eggs of 125 kg female Huso huso in Shahid Marjani Sturgeon propagation center (Agh Ghala, Golestan province). The fries of bester and control treatment of beluga were transported to International Sturgeon Research Institute (Rasht) after about one month by reaching to 490 mg and 377 mg of weight respectively. All fishes fed by artificial concentrated food (48-50% protein and 15-17% fat) after a period of feeding with Artemia and Daphnia. Sorting was carried out according to increase of fish weight for both fishes. Results showed that the imported sterlet spawners were not at the high maturation stages and especially the males had not suitable sperm quality. It showed that up to 2 months of age , these was no significant difference between bester and beluga weight but from this age up to 2 months of age the weight of beluga was greater. Meanwhile from 2 months old up to the end of the study (21 months) the weight of bester sample was significantly greater than beluga. The comparison of FCR for the whole rearing period showed no difference between bester and beluga (2.4 and 2.3 respectively). In general, the increase and decrease pattern of GR and SGR were coincided to each other, but showed monthly differences. Growth rate (GR) and specific growth rate (SGR) of bester were greater than beluga from 4th and 3rd month of rearing period respectively

    Investigation of chromosome and ploidy levels of rainbow trout produced from imported eyed eggs

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    Rainbow trout is the main cultural species of coldwater fishes in iran. Often, aquaculturists intend to breeding in order to production of lines with higher growth rate potential and disease resistant. Nevertheless in the country, no trout breeding programs, has been performed yet and most of the farms focused on the cultivation of the first (unbred) race. While European countries progressed in trout breeding techniques and production lines with higher growth through genetic manipulation (chromosomal number and type changes of fish) and/or selection and their fish products derived from this technology, including eyed eggs and so on have sold to other regions of the world (eg: Iran). In this study, some biological parameters including survival, growth, feed conversion ratio (FCR.) and chromosomal number of two juvenile groups from imported( group 1) and native(group 2) eyed fish eggs were compared. For chromosomal investigation, blood smear test and flow cytometry were performed. sults showed a significant difference (P≤5%) in growth rate of native fishes and French group Native fish feed conversion ratio (0.9) was significantly difference (P≤5%) from that of French fishes (1.15). Chromosomal analysis showed no difference in chromosome number in treatments and two fish groups were 2n chromosome. Based on the results, the fishes of group 1 had faster grow potential and gain weight in less time than that of group 2 and this has been achieved to go through the process of selection and feminization without any change in number of ploidy. Whereas the ability of native fishes in food efficiency ( lower FCR.) was better. However, the reduction of rearing period is the benefit and preference of cultivation of imported or origionally foreign

    The fifth developing plan of Iranian Fisheries Research Institute

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    Accurate scientific and practical plan for achieving the goals of the Islamic Republic of Iran within the framework of Vision development 1404, is the infrastructure achieving sustainable development of the country. Order to achieve the above mentioned objectives and in order to the comprehensive development plans in the country, Iranian fisheries research organization adjust the fifth developing plan for support of executive related departments in country with mobilization a large number researchers consists of several working groups of ifro affiliated research centers. The fifth developing plan consist of three chapters for report of the forth developing plan and intrudction of research, construction plans and financial support (budjet) for period of 2011-2014 A.C

    Modeling habitat preferences of Caspian kutum, Rutilus frisii kutum (Kamensky, 1901) (Actinopterygii, Cypriniformes) in the Caspian Sea

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    Predicting and modeling of habitat preferences of fish is a very important issue for aquatic management. Classification trees (CTs) were used to predict the habitat preferences of the Caspian kutum (Rutilus frisii kutum, hereafter kutum) in the southern Caspian Sea. The applied model was optimized with genetic algorithm (GA) and greedy stepwise (GS) to select the most explanatory variables for predicting the presence/absence of kutum. The suitability index was considered to determine the quality and suitability of fish habitat in the sea. The results of Paired Student's t tests showed that there was a significant difference between predictive performances of models before and after variable selection methods. Both optimizers improved the predictive power of CTs and resulted in a better understanding of CTs by making a selection of the sea characteristics that were used as inputs to the models. The results show that the effect of different seasons, sea depth, and photosyntheticaly active radiation were the main predictors affecting the habitat preferences of kutum in the Caspian Sea. Constructed trees in combination with GA and GS showed high capability when applied to predict the habitat preferences of this valuable commercial fish species. Determining the habitat needs of the target fish will enhance local fisheries performances and the long-term conservation planning of the fish to implement the ecosystem-based management in the Caspian Sea
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