ALBERT

Description: Due to having so many commercial fish species, the Caspian Sea has special importance. In order to enhancement and restocking of some fish species such as kutum, bream, pike perch and common carp that their stocks were under damage, shilat company annually released fingerlings of these species into the river of Iranian part of the Caspian sea specially for kutum, bream and pike perch in Guilan province. Monitoring and surveying of fingerlings releasing in quality and quantity point of view, from loading to offloading place was done by fisheries research center of Guilan province. The mean number of fingerlings per loading in 2000 was about 11808 with minimum and maximum of 30000 and 616000 fingerlings Respectively, The caring time from culturing pond to the western river of Guilan was more than the same for eastern rivers; but the number of fingerlings per loading for western rivers were much more with. Comparison to eastern one and it is recommended .that the, fingerlings density per, loading should be adjusted by, distance that is better to be much' more for near distance. The weight range of fingerlings was recorded as 0.55 to 1.6 gr with an average of 1.02 gr. The fingerlings: release of kutum to the rivers such as Chalvand, Lemir, Kargan roud, Navroud, Khalehsara, Anzali lagoon, Sefid roud, Chamkhaleh and Khoshk roud were 1.01,6.4 milions respectively. Totally, 79087605 •fingerlings of kutum released to the Guilan province rivers. The most kutum fingerling released, had a weight range of 0.6 to 1 gr (56.6 milions fingerlings). Also the peak of releasing was in August (31.7 milions fingerlings). Surviving rate of kutum in 1991 was estimated 8.4% e That showed 16% decrease-with„comparison-to-1996-and-1-99-7.In study of parasitic diseases in fingerlings Diplostomum (digen), Tricodina, giroductylus (monogen) were recognized, among these, Diplostomum was more important for pathogenesis. The percent of contamination by diseases in 2000, highly decreased in comparison to 1995. The rate of pike perch fingerlings release from 1990 to 2000 had an increasing trend and from 16000 fingerlings in 1990 reached 3.8 million fingerlings if 2000.¯Nümber Si li on s-respectively-he-mean number fingerlings per loading for the above mentioned rivers were 103467, 76227, and 89300 fingerlings respectively. Pike perch fingerlings released in May (2.5 million fingerlings) and gune (0195 million fingerlings). Released number of Pich perch fingerlings peaked in weighting range of 0.5-1 gr and average weight of fingerlings was 0.9 in 2000. Although some fingerlings were released below 0.5 gr. During 10 years ago the catch of bream is to be grow up gradually and had some fluctuations. Totally, 14.5 milions of bream fingerlings were released in to the Anzali lagoon, the number of fingerlings per loading was 75057 with minimum and maximum of 11200' to 140000 fingerlings respectively. Mean weight of bream fingerlings in 2000 was better than previous years and reached 1.15 gr. releasing of bream fingerlings was in July (7948250 fingerlings) with average weight of 1.4 gr, but in August this figure decreased to 0.75 gr. The weight range of released bream fingerlings was 0.5-2.2 gr and maximum number of released fingerlings had a weight range of 0.6-1 gr. return coefficient of bream in 1993 was 1% which showed decrease in comparison to 1991.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: Given the advancement of electronic technologies and the impact of its application on the environment, especially aquatic ecosystems, it is necessary to address its various aspects, to be attended its various aspects, particularly about electromagnetic waves and their effects on fish as the most important aquatic animal with economic aspects. The present study was designed to reduce the dramatic decline in the production of ornamental fish, in particular the koi fish in Zanjan province, and the research application of the provincial fisheries department to investigate the effects of environmental electromagnetic waves as one of the important alternatives to reduce the proliferation of koi fish. In the present study, the effect of mobile electromagnetic waves (900 MHz) on gonadosomatic index (GSI) and Hepatosomatic index (HSI), Luteinizing Hormone (LH), and gonadal tissue structure of male and female fish brooders during 10 days and in 3 experimental groups including: control (without receiving waves), treatment 1 and treatment 2 (each one, 4 times a day and each time for 30 minutes in faced with mobile phones in standby position and calling mode, respectively). Biometry of broodstocks, blood sampling from caudal vein, centrifuge and serum isolation, determination of RBC, WBC, Hb, Hct, MCV, MCH, and LH, dissection, GSI and HIS calculation, Gonadal sampling, and classical histology were done at the end of the experiment. The success of reproductive production in males and females was more than the other two treatments. In both sexes, the HSI index of treatment 2 significantly increased. The lowest mean of RBC, Hb and Hct was in broiler breeders, and the highest levels of WBC and neutrophil and the lowest percent of lymphocyte in male broodstocks belonged to treatment 2. Histological results showed that the number of ovaries in treatment 1 and 2 was significantly higher than control. Atresia and defects in the previtellogenic and vitellogenic oocytes and degeneration in nuclei, cytoplasm, vitelline envelope and membrane folliclar cells were found in the ovarian tissue of the treatment groups 1 and 2. In gonad of male broodstocks, the mean of large and small diameters and the mean of area and perimeter of the testis lobules, and the sperm occuping the lumen of the testis lobules in treatments 1 and 2 were less than control. Epithelial thickness and tissue defect of treatment 1 and 2 were higher in the control group. The histopathological signs observed in the testis tissue of the brooders in treatment 1 were: Degeneration and breakdown in the testis lobul epithelium, abnormal lobular structure, lumens filled with inactive or anomalous spermatogonies and pre-existing of nucleos of sperm cells, testis tissue necrosis, thickness and fibrosis of epithelial wall of lobuls, and cellular degeneration In some of the lobules, and in treatment 2: degeneration and destruction of stroma in some lobules, degradation in a significant part of the testicular tissue, the appearance of alveolus in epithelium cells (destruction of the germ cell nucleus), fibrosis, and filamentation in the epithelium of lobules, thickness and breakdown in the epithelium of the lobules, in some places, and extensive vacuolization in the lumen of the lobules was observed. In general, the results showed that mobile-induced electromagnetic waves (frequency: 900 MHz, wavelength: 1-103 mm) produced numerous negative biological effects on female and male of koi fish, especially male brooders. So, with providing the necessary conditions for reproduction in Koi brooders (including: the temperature of water near 20 ° C, the oxygen level is at least 5 mgL-1, Non-ionized ammonia and nitrite levels of less than 0.05 mgL-1 and pH range near 7), it should be avoid to use of electromagnetic devices, especially mobile phones at the hatcheries and in the adjacent of fish tanks at the reproduction time.

Description: Published

Description: The study was done in Nutrition and Live Food Station was located in Bandar Anzali Ghaziyan. Juveniles weighted average 0.5, 1, 2.5, 5, 10, 15 and 20 g were randomly selected in three water conditions with a salinity of 11 ppt (Caspian sea water), water 7 ppt and freshwater (with three replicates per group) were included. At intervals of 0, 3, 6, 12, 24, 72, 168, 240 hours, blood samples were heparinized capillary tubes by caudal juveniles and ion concentrations Mg, Ca,Cl using the spectrophotometer and sodium and potassium ions with Flaym photometry (flame photometric), the osmotic pressure of blood plasma by osmometer and cortisol levels were measured by RIA method. To study the microstructure of gill and kidney tissue for each treatment , tissue samples by classical histological methods and stained with hematoxylin - eosin slides were prepared. The frequency and location of the enzyme Na^+, K^+ - ATPase and chloride cells with immunohistochemical localization was performed. Studies micrometric gill chloride cells and renal glomerular networks by software Image tool (version 2.0) was performed. Measurement of enzyme Na^+, K^+-ATPase, by Zaugg (1982) method was conducted. Data analyzed by one-way ANOVA (Oneway ANOVA) with Tukey's test was performed. Overall, the results of measuring ions and osmotic pressure on the tenth day of treatment, the osmotic potential juveniles 2.5, 5, 10, 20 gr in Caspian sea water and all groups except the 0.5 in water of 7 ppt confirmed. But in case of unfavorable conditions for the release in estuaries river and river, fish with weight 1 to 3 release directly to beach (where the salinity is 7 grams per liter) and fishes with weight from 10 to 20 gr to sea. Although suitable river conditions necessary condition for release of juveniles in riverine areas to adaptation juveniles occur gradually.

Description: This study was carried out to determine the appropriate size of Caspian trout (Salmo trutta caspius Kessler, 1877) juveniles for releasing to South Caspian Sea or possibility of cage culture in Caspian Sea water. 1611 specimens were exposed in 4 weight groups of 5, 10, 15 and 20 g, in 3 salinity trials: Caspian Water (11- 11.5), inshore water (7) and fresh water (control). Each trial was done in 3 replicates. The blood samples and tissue fixations carried out from juveniles of control group (in fresh water) and 3, 6, 12, 24, 72, 168, 240 hours after exposure of fish in different treatments. Plasma osmolal ity, Na^+ and Cl^- concentrations, were measured by osmometer, flame photometer, RA1000 respectively. Plasma cortisol level was determined by using RIA (radio immunochemical assay). Na^+, K^+-ATPase activity in homogenates of gills was estimated by phosphate released from ATP. Histological indicators including chloride cell diameter and nephron morphometric parameters were assessed using classic preparation and optic microscope with digital camera. Results of osmolality and ions measuring concurrently show that all weight groups can live in salinity of 7 and they maintain the osmolality and ion concentrations. In the Caspian water, weight groups excluding 5 g juveniles show same result. Mean plasma osmolality of 20, 15, 10 and 5 gr juveniles in control group (time of 0) were calculated 331.3±8.7, 307.7±6, 334.7±14.6 and 301±8.7 mosml/l. This parameter in the above weight groups after 240 hours exposure in the Caspian Sea water were measured 329±0.53, 321±9, 325.3±6.7 and 346.5±13.6 respectively. The observation of kidney glomeruli in histological sections shows that the diameter of glomeruli in 5, 10, 15 g weight groups in 7 and all groups in Caspian water decreased after 72 h adaptation period (p〈0.05). The cortisol level in 5g juveniles increased (p〈0.05) after 168 hour of the exposure (106±11.3 ng/ml) by comparison with control group (79.5±38 ng/ml). The changes of cortisol level in other groups were not significant. The number of gill chloride cells after 7 days of fish exposure in Caspian Sea and in water of 7 salinity was not changed significantly (p〉0.05) for 5g juveniles, whereas within weight groups of 10, 15 and 20 g in Caspian Sea water and groups of 15, 20 g in water of 7 salinity, the increase (p〈0.05) of chloride cells was observed. The amount of chloride cells on gill secondary lamellas in mentioned trials varied up 3 to 7 (between two lamellas on the histological sections of 5 thickness). The size of chloride cells in 5g juveniles in different salinities has not changed (p〉0.05), although in other groups, a significant increase of this parameter was detected during experiments. Na^+ ,K^+ -ATPase activity in juveniles of 5g weight group in 7 salinity and Caspian water was low (3.2 6.1 mol Pi /mg protein/ h). The enzyme activities in all weight groups were higher under the exposure in Caspian Sea water than that in water of 7 salinity. In group of 10 g juveniles at start time (control in freshwater) the activity of Na^+, K^+ -ATPase was significantly higher (p〈0.05) than that in 20g group. It is may be related to some metabolic changes and transforming to parr-smolt.

Description: The study was done in Nutrition and Live Food Station was located in Bandar Anzali Ghaziyan. Juveniles weighted average 0.5, 1, 2.5, 5, 10, 15 and 20 g were randomly selected in three water conditions with a salinity of 11 ppt (Caspian sea water), water 7 ppt and freshwater (with three replicates per group) were included. At intervals of 0, 3, 6, 12, 24, 72, 168, 240 hours, blood samples were heparinized capillary tubes by caudal juveniles and ion concentrations Mg, Ca,Cl using the spectrophotometer and sodium and potassium ions with Flaym photometry (flame photometric), the osmotic pressure of blood plasma by osmometer and cortisol levels were measured by RIA method. To study the microstructure of gill and kidney tissue for each treatment , tissue samples by classical histological methods and stained with hematoxylin - eosin slides were prepared. The frequency and location of the enzyme Na +, K + - ATPase and chloride cells with immunohistochemical localization was performed. Studies micrometric gill chloride cells and renal glomerular networks by software Image tool (version 2.0) was performed. Measurement of enzyme Na +, K +-ATPase, by Zaugg (1982) method was conducted. Data analyzed by one-way ANOVA (Oneway ANOVA) with Tukey's test was performed. Overall, the results of measuring ions and osmotic pressure on the tenth day of treatment, the osmotic potential juveniles 2.5, 5, 10, 20 gr in Caspian sea water and all groups except the 0.5 in water of 7 ppt confirmed. But in case of unfavorable conditions for the release in estuaries river and river, fish with weight 1 to 3 release directly to beach (where the salinity is 7 grams per liter) and fishes with weight from 10 to 20 gr to sea. Although suitable river conditions necessary condition for release of juveniles in riverine areas to adaptation juveniles occur gradually.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: This study was carried out to determine the appropriate size of Caspian trout (Salmo trutta caspius Kessler, 1877) juveniles for releasing to South Caspian Sea or possibility of cage culture in Caspian Sea water. 1611 specimens were exposed in 4 weight groups of 5, 10, 15 and 20 g, in 3 salinity trials: Caspian Water (11- 11.5 ), inshore water (7 ) and fresh water (control). Each trial was done in 3 replicates. The blood samples and tissue fixations carried out from juveniles of control group (in fresh water) and 3, 6, 12, 24, 72, 168, 240 hours after exposure of fish in different treatments. Plasma osmolal ity, Na+ and Cl- concentrations, were measured by osmometer, flame photometer, RA1000 respectively. Plasma cortisol level was determined by using RIA (radio immunochemical assay). Na+, K+-ATPase activity in homogenates of gills was estimated by phosphate released from ATP. Histological indicators including chloride cell diameter and nephron morphometric parameters were assessed using classic preparation and optic microscope with digital camera. Results of osmolality and ions measuring concurrently show that all weight groups can live in salinity of 7 and they maintain the osmolality and ion concentrations. In the Caspian water, weight groups excluding 5 g juveniles show same result. Mean plasma osmolality of 20, 15, 10 and 5 gr juveniles in control group (time of 0) were calculated 331.3±8.7, 307.7±6, 334.7±14.6 and 301±8.7 mosml/l. This parameter in the above weight groups after 240 hours exposure in the Caspian Sea water were measured 329±0.53, 321±9, 325.3±6.7 and 346.5±13.6 respectively. The observation of kidney glomeruli in histological sections shows that the diameter of glomeruli in 5, 10, 15 g weight groups in 7 and all groups in Caspian water decreased after 72 h adaptation period (p〈0.05). The cortisol level in 5g juveniles increased (p〈0.05) after 168 hour of the exposure (106±11.3 ng/ml) by comparison with control group (79.5±38 ng/ml). The changes of cortisol level in other groups were not significant. The number of gill chloride cells after 7 days of fish exposure in Caspian Sea and in water of 7 salinity was not changed significantly (p〉0.05) for 5g juveniles, whereas within weight groups of 10, 15 and 20 g in Caspian Sea water and groups of 15, 20 g in water of 7 salinity, the increase (p〈0.05) of chloride cells was observed. The amount of chloride cells on gill secondary lamellas in mentioned trials varied up 3 to 7 (between two lamellas on the histological sections of 5 thickness). The size of chloride cells in 5g juveniles in different salinities has not changed (p〉0.05), although in other groups, a significant increase of this parameter was detected during experiments. Na+ ,K+ -ATPase activity in juveniles of 5g weight group in 7 salinity and Caspian water was low (3.2 6.1 mol Pi /mg protein/ h). The enzyme activities in all weight groups were higher under the exposure in Caspian Sea water than that in water of 7 salinity. In group of 10 g juveniles at start time (control in freshwater) the activity of Na+ ,K+ -ATPase was significantly higher (p〈0.05) than that in 20g group. It is may be related to some metabolic changes and transforming to parr-smolt.

Description: Iranian Fisheries Science Research Institute

Description: Published