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برخی خصوصیات زیستی ماهیان ازون برون Asipenser stellatus در آبهای گیلان -1373 | ||
| مجله علمی شیلات ایران | ||
| مقاله 5، دوره 6، شماره 1، فروردین و اردیبهشت 1376، صفحه 49-64 اصل مقاله (1.02 M) | ||
| نوع مقاله: مقاله پژوهشی | ||
| شناسه دیجیتال (DOI): 10.22092/isfj.1997.116315 | ||
| نویسنده | ||
| داود غنی نژاد | ||
| چکیده | ||
| برخی خصوصیات زیستی ماهیان ازون برون Asipenser stellatus در آبهای گیلان -1373 | ||
| کلیدواژه‌ها | ||
| ماهیان ازون برون Asipenser stellatus؛ استان گیلان | ||
| عنوان مقاله [English] | ||
| On Some Biological Aspects of Acipenser stellatus in the South West of the Caspian Sea in 1994 | ||
| نویسندگان [English] | ||
| D. Ghaninezhad | ||
| چکیده [English] | ||
| During the fishing season, the statistical study on biological observation was carried out in four fishing stations located in the south west of the Caspian sea. During the research activity 2806 stellate sturgeon were sampled. The resualt revealed that the ratio of stellate eggs weight used in processing of caviar were 20.7% of the total weight of the body. The number of females were more than males in the catch (77.8%) . In 1991 the average lenght of females was 134.1 cm and the average weight with internal organs was 11.86 kg. But the mean lenght and weight in 1993 were 120.5 cm and 11.6 kg. The average age for female and male were estimated 12 and 10 years old respectively. Among the samples 92.7% of females were in the fourth stage of maturity and 60.4% of males were in third stage of maturity. In spite of the fact that during 1984-1991 fishing effort for catching Acipenser had been increased, yielding caviar had been decreased. This state was continued until 1994. So it was revea..... | ||
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