نتایج جستجو برای: kutum
تعداد نتایج: 547 فیلتر نتایج به سال:
The present study examines the developmental stages of the eye retina in Caspian kutum during the pre-hatch stage to end of the larval stage. Fertilized eggs of Caspian kutum were obtained from Shahid Ansari Center for Reproduction of teleost fish (Guilan province, Iran). Sampling was done for one month until the larval stage completed and the yolk sac completely depleted. Samples were studied ...
currently, white fish or kutum rutilus frisii is considered to be a good candidate for commercial aquaculture. however, little information is available regarding the nutritional requirement of this fish fry. experiments were conducted to examine the effects daphnia magna as live food cultured on two freshwater green algae, chlorella sp. and scenedesmus obliquus enriched with different b group v...
The ontogenesis and specific activities of pancreatic (trypsin, chymotrypsin, amylase and lipase) and intestinal enzymes (alkaline phosphatase, aminopeptidase N) were investigated in Kutum (Rutilus frisii Kutum) from the onset of exogenous feeding (3 day after hatching, DAH) to the juvenile stage at 50 DAH. Trypsin- and chymotrypsin-specific activity showed similar patterns and increased with l...
Caspian kutum, Rutilus frisii kutum, is one of the most commercially important fish species in the Caspian Sea, but there are few reports about the endocrinology of induced spawning in this fish. In the present study, 54 individuals of female broodstocks of Kutum were studied for quantity and quality of propagation index, during March and April 2007. Hormone treatments include: LHRH-A2 (1 ?g kg...
The growth and mortality coefficient of Rutilus frisii kutum, were estimated using length frequency data collected in southern waters of the Caspian Sea during October 2008 to April 2009. The following population parameters were evaluated: length-weight relationship, W = 0.004L 3.258, (r= 0.976) Von Bertalanffy growth constants, W∞ (g) = 4192.3, L∞ (cm) = 70.45, K = 0.2, per year t0 = −0.75 tot...
This study was conducted to evaluate the effects of different levels of Mentha piperita extract on growth factors, survival rate and body composition of Rutilus frisii kutum fry. For this purpose, four groups of fish with mean weight of 1.12± 0.14 g were raised for 56 days in plastic tanks (40 fish to each tank) and feeding with different levels of M. piperita with concentrations of 0, 1, 2.0 a...
Proper storage density affects the growth and rearing of fish. This experiment was carried out to investigate the effects of rearing densities on the growth and carcass composition of Caspian kutum (Rutilus frisii) fry and physicochemical factors of farming water. Fish were examined in five rearing densities (5, 10, 15, 20, and 25 fish/60 L of water) with three replications, and fed based on 8%...
یکی از مسائل مهم در بازسازی ذخایر ماهی سفید، دسترسی به مولدین با کیفیت مطلوب می باشد. این مطالعه با هدف مقایسه شاخص های زیستی، خونی و تولید مثلی در مولدین ماده ماهی سفید در دو رودخانه تجن و شیرود طی سال های 87-85 صورت گرفت. تعداد 30 عدد مولد ماده (در هر دوره تکثیر) از دو رودخانه صید شده و از نظر شاخص های زیست سنجی، خونی و تولید مثلی مورد مقایسه قرار گرفتند. نتایج نشان داد که ماهیانی که به رودخا...
تحقیق حاضر به مطالعه تاثیر دافنی (daphnia magna) غنیشده با روغن کبد ماهی کاد و کلزا بر فاکتورهای رشد و بازماندگی لارو ماهی سفید به مدت چهارده روز از ابتدای تغذیه فعال پرداخت. لاروهای ماهی سفید با وزن اولیه ۱۱/٢±٦/۵٢ میلیگرم با تراکم ده عدد در هر لیتر آب در قالب طرح کاملاً تصادفی با سه تیمار غذایی شامل دافنی غنیشده با روغن کبد ماهی کاد، دافنی غنیشده با روغن کلزا و دافنی غنینشده تغذیه شدند. م...
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