جستجوی مقالات مرتبط با کلیدواژه "کلمه" در نشریات گروه "شیلات"

Cu is an essential micronutrient which is found in either water environment or fish diet. In addition, copper sulfate is an effective algaecide for algal control in fish pond. Therefore, toxicity test seems to be necessary to predict the safe concentrations of chemicals in the environment. The experiments were conducted to study of mortality rate of acute toxicity of Copper (CuSO4) in Common Carp (Cyprinus carpio) and Caspian kutum (Rutilus caspicus) fry.13 fishes with average weight of 2±0.5 and 20±2.2g to R. caspicus and C. carpio  respectively were exposed to different concentrations of copper salt respectively. The experiments were done by Static Method during 96 hours. In the experiments, the different concentrations of copper such as 0, 0.1, and 0.2, 0.3, 0.4, 0.45 and 5mgL-1 were used. Under stable condition (T= 25±1OC, pH=7.8 ± 0.2), the lethal concentration of copper (LC50) was measured of 0.4mgL-1 and 0.45mgL-1 to R. caspicus and C. carpio respectively during of 96 hours. There were significant differences between treatments with each other and also with the control (P<0.05). So, with increasing of copper in each treatment, the mortality rate of fish significantly was increased. For studying histopathological, 3 fish were selected randomly from each treatment and after killing fish, samples of liver, kidney, and gill tissue were taken from each fish. These samples (sections) were stained with Hematoxylin-Eosin and then the impacts of Cu on the fish organs were studied under light microscope. Histopathological findings showed that major lesions were hemorrhage, hyperemia, hyperplasia and epithelial cells necrosis, degenerated tubules of their kidney, expansion of Bowmanchr('39')s capsule and hepatocytes necrosis in 0.3, 0.4 and 0.45 concentrations respectively. There were any lesions in control.

Summary: The catch of Carp (Cpinus carpio) and Roach (Rutilus caspicus) in the southern waters of the Caspian Sea, especially in Golestan province, have been a special status because the major catch of these two species in the Caspian Sea are related to the eastern coast of the Golestan province. This study was conducted to investigate the effect of the size and numbers of fingerling released into the Gorganroud River, decline of the water level in the Caspian Sea and discharge of the river on cpue (catch per unit effort) of these two species. For this purpose, the data on catch and release of two species carp and roach yearly during 1999-2017 from fisheries organization, the data of changes in the Caspian Sea level from the Caspian Sea Research Center and information related to discharge of river water from the Golestan Meteorological Office were prepared. The catch rate and the number of released fingerling of two species carp and roach were fluctuated during this period. During the last four years, the catch share of C. carpio and R. caspicus in Golestan province was decreased in comparison to the total catch rate of these species in the Iranian waters of the southern coast, while the number of release in these four years was increased. The results of this study showed that different factors (sea level, released weight, and released number) simultaneously affect the rate of catch per unite effort (cpue) of two species of carp and roach.

In this study, length-weight relationship of three populations of fingerling roach (Rutilus rutilus caspicus), wild, farmed and mix were investigated with the fish reproduce in the center of the proliferation of bony fish Syjeval Harber. In order to check the length-weight, 587 sample fish by hand Sachook during the release into the sea. Minimum and maximum total length of respectively 17.14 (farmed) and 73.93 (wild) mm and the minimum and maximum total weight of 0.061 (wild) and 3.198 (wild) g. The mean length and weight in wild specimens, respectively 41.602±0.142 cm and 0.817±0.054 g, farmed 41.476±0.116 cm and 2.107±0.691 combined heat and 38.376±0.128 cm and 2.943±0.500 g. Parameter values b, to wild populations, breeding and combined respectively 2.580, 2.505 and 2.450 was estimated that the amount and probability of close to 3 positive allometric growth pattern for the fish population in the three certificates Gives. The average Condition Factor in wild populations, breeding and combined respectively, 0.900, 0.832 and 0.842 respectively. To results It seems that the growth parameter of wild fish is better than breeding and synthentic populations.

This study was conducted to determine some biological characteristics of migration population of roach, rutilus caspius including age, growth and reproduction in Gomishan wetland from early November 1999 to early December 2000. The sampling were carried out monthly but in the peak of spawning period (late February to mid April) it was done weekly. The sex ratio was found M:F=1.17:1.00 without any significant difference (even at 10% level); but the results of the sex ratio for each separate age group showed significant difference (p< 0.05). A significant correlation was determined between total lengths, body weight, scale radius and age Based on back calculation, the maximum growth rate were found in ages 1+ and 2+ Gonadosmatic index (GSl) was age-dependent; with two peaks or late February and early March for males und late March and early April for females. The eggs diameter was measured with a range from 0.9 mm to 1.45 mm and the absolute fecundity was related to age......