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This study was carried out to show the effects of herbal supplement of Sangrovit on the growth parameters, blood biochemical factors, survival and resistance to salinity of the Caspian kutum fry. Fish (1±0.003 g) were divided into four groups fed on diets containing sangrovit at different levels: 0 (control), 0.05, 0.1 and 0.15 % for 45 days. The results showed that there was a significant increase in the final weight, weight gain and specific growth rate of the fish fed on sangrovit diets (p<0.05). In addition, food conversion rate of fish fed on sangrovit diet was found to be significantly (p<0.05) lower than the control group. However, there was no significant difference in the condition factor, glucose and total protein levels of the experimental groups and the control group (p>0.05). On the other hand, blood cholesterol of the Caspian kutum was significantly increased in the control group (190.17±0.013 mg dl^-1) in comparison to treatments sangrovit (p<0.05). Survival and resistance to salinity stress remained unaffected by dietary supplementation of sangrovit (p>0.05). The results of the present study also indicated that dietary Primalac beneficially affected the growth performance and blood biochemical parameters of the Caspian kutum fry. The findings of the present study indicated that the herbal supplement of sangrovit could improve the growth rate, feed utilization and blood biochemical parameters of the Caspian kutum fry.

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This study was conducted in order to measure glucose, cholesterol and hematocrit as indicators to evaluate the effect of caraway seeds meal (CSM) on the health and resistance of common carp to salinity stress. To attain this goal, fish (2.457±0.057 g) were divided into four groups fed on diets containing different levels of CSM; 0 (control), 0.5, 1 and 1.5%. After 56 days of feeding, blood samples of the fish were obtained in five stages (once before and four times after stress) to evaluate glucose, cholesterol and hematocrit levels. The experiments indicated that salinity sign-ificantly affected glucose, cholesterol and hematocrit. On the first day after stress, the hematocrit and glucose levels were considerably increased in all groups compared with their levels before stress. After stress, cholesterol level signif-icantly decreased in all groups compared to before stress. The level of hematocrit indicated no significant difference among the groups before and after stress. On the first day after stress, the glucose levels significantly increased in trea-ted groups with CSM compared with the control group. The glucose and hematocrit levels were decreased gradually in all groups from the third day on. After stress, no differences were observed for survival rates among the experimental diets. However, the highest survival rate belonged to treated groups with CSM. The overall result indicated that the suplement of CSM has a positive influence on the glucose, hematocrit and resistance of common carp to salinity stress.

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Feeding frequency and stocking density are important factors affecting growth and maturation of cultured fishes. The aims of this investigation were to determine the effects of stocking density (10, 20, 30 and 40 fish per aquarium) and feeding frequency (2, 3 and 4 times per day) on growth parameters and hematocrit of the Rutilus rutilus caspicus. The experiment was continued for 45 days in two replicates. The results of this study showed that growth parameters, including weigh gain (WG), feed conversion ratio (FCR) and specific growth rate (SGR) were affected significantly by stocking density (P<0.05), but not significantly affected by feeding frequency (P>0.05). The highest WG and SGR were recorded with the lowest stocking density (10 fish / aquarium). The least FCR was obtained in density of 10 fish/aquarium, FCR value was significantly higher with high stocking density (P<0.05). Also, interactions between stocking density and feeding frequency were no significant on growth parameters (P>0.05). Density and feeding frequency hand no significant effect of hematocrit concentration (P>0.05). On the other hand, interactions between stocking density and feeding frequency significantly affected hematocrit levels (P<0.05). The lowest level of hematocrit was observed in density of 10 fish/aquarium at two times / day feeding frequency. The results of this study indicated that density is significantly affected the growth, but increasing of feeding frequency there is not effect on growth in the Rutilus rutilus caspicus.
 

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Sex steroid hormones play important roles in many physiological processes, particularly in the reproduction of teleostei. Therefore, study of steroid hormones in fish is one of the important indicators of reproductive biology. In the present research, serum steroid hormones such as testosterone (T), 17β-estradiol (E2) and progesterone (P) in Esox lucius brood stocks, during one year, from autumn 2010 to summer 2011, in five periods (autumn, first half of winter, second half of winter, spring and summer) with three longitudinal classes: 300-360, 360-420 and 420-480 millimeters were studied. The results showed significant difference between levels of steroid hormones in three longitudinal classes and showed an increasing trend by increased length (P<0.05). In addition, there was significant different between levels of gonadal steroid hormones and different seasons (P<0.05). The highest level of 17-β estradiol was observed in autumn season. In the case of testosterone and progesterone hormones, higher levels were recorded in first and second half of winter, respectively.