ميگو وانامي( ( Litopenaeus vannamei بدليل تحمل و سازگاري با شرايط مختلف اكولوژيك و نيز تراكم پذيري در شرايط پرورش بعنوان يكي از گونه هاي مهم براي توسعه آبزي پروري محسوب مي گردد. هدف از اين مطالعه تعيين بيونرماتيوهاي پرورش ميگوي وانامي با آب لب شور درياي خزر در استان مازندران و نيز امكان سنجي معرفي يك گونه جديد آبزي پرورشي در استان بوده است. اين تحقيق در تايستان 1391، 1393 و1394 و در محل پژوهشكده اكولوژي درياي خزر با آب لب شور(ppt43/0±52/10) درياي خزر در استان مازندران انجام شد. در اين مطالعه اثر تراكم هاي مختلف (45، 50، 55 و60 عدد در متر مربع) ، ذخيره سازي اوليه پست لارو ميگو وانامي (PL12) بر ميزان رشد و بازماندگي و نيز بررسي ساختار جمعيت فيتوپلانكتون در استخرهاي پرورش مورد ارزيابي قرار گرفت.
در سال 1391پس از سازگاري پست لاروها با آب لب شور درياي خزر با تراكم 35 قطعه در مترمربع دريك استخر خاكي هزار متر مربعي ذخيره سازي شد. بعد از پايان دوره پرورش(85 روز) ، متوسط رشد روزانه 037/0±31/0 گرم، ميانگين وزن 71/0±11/21 گرم، ضريب تبديل غذايي 79/0، درصد بازماندگي 73 درصد و محصول نهايي به ميزان 539 كيلوگرم بدست آمد. در سالهاي 1393 و 1394 نيز در طي 90 روز پرورش در استخر بتوني با تراكم 40 قطعه در متر مربع، ميانگين وزن 20 و 18گرم و ضريب تبديل 68/0 و 77/0 درصد بترتيب كسب شد. آزمايشات مربوط به اثر تراكم هاي مختلف يطور جداگانه در سال 1391 در 12 استخر مدور بتني با بستر ماسه اي (به مساحت 78 متر مربع) در 4 تيمار آزمايشي و هر تيمار شامل 3 تكرار انجام شد. دوره پرورش 75 روز و ميانگين دماي آب در طول دوره پرورش 79/1±4/27 درجه سانتي گراد بوده است. نتايج نشان داد كه بين ميانگين پارامتر هاي رشد و بازماندگي در تيمار هاي آزمايشي تحت آزمون دانكن، اختلاف معني دار آماري وجود دارد (05/0>P). بدين ترتيب كه با افزايش تراكم ميزان افزايش وزن و نرخ بازماندگي (SR)، ضريب رشد ويژه (SGR) و ضريب رشد روزانه (ADG) كاهش يافته و همچنين تغييرات ضريب تبديل غذايي در تيمار ها متفاوت بود (05/0
چكيده انگليسي :
Abstract
Whiteleg shrimp (Litopenaeus Vannamei) is one of the most important species for aquaculture development, because of tolerance and adaptation to different ecological conditions.The aim of this study was determine the bionormative parameters of vannamei shrimp culture using Caspian Sea brakish water in Mazandaran province and also possibility of introduction a new aquatic spciese for rereaing in Mazandaran province. The Shrimp vannamei reared with the brackish water (10±0.43ppt) of the Caspian Sea in Mazandaran province and the Caspian Sea Ecological Research Iinstitute in summer 1391, 1393 and 1394. In this study, were evaluated the effect of different densities (45/m2, 50/m2, 55/m2 and 60/m2) primary stock whiteleg shrimp postlarvae (PL12) on the growth, survival rate and also population structure of phytoplankton in shrimp vannamei. Initially, post larvae in brackish water were gradually adopted. The density of 35 per square pieces in an earthen pond (1000m2) was stocking.The rearing time was 85 days. Average daily growths: 0.31±0.037g; final mean weight: 21.11±0.71; Feed conversion ratio: 0.79 and final yield: 531kg were determined.
In addition the experiment of 1391, the results of Mazandaran province vannamei shrimp culture, were observed in 1393 and 1394, the average weight average daily growing and FCR % were 20-18 g and 0.68 - 0.77 respectively during 90 days culture period with harvesting of 40 PL /m2 at cement culture pond. The experiments of effect of different densities were performed separately in 1391, in 12 circular concrete pound with a sandy bed (area: 78m2) in the four treatments and three replications for each treatment. The experiments performed in a 75-day period. During the test, the water temperature was 27.4±1.79°C. The results showed that growth parameters and survival rate in experimental treatments, there was a statistically different (Duncan test, P<0.05). Thus, with high levels of density, the amount of weight gain and survival rate (SR), specific growth rate (SGR) and daily growth rate (ADG) has decreased. In addition, the treatments were different variations of FCR (P<0.05) and not depend on the primary stock density of postlarvae. The highest growth (SGR=11±0.04 and ADG=0.25±0.01) and survival rate and calculate the amount of production per hectare (5596±433) were observed in low density (45m2). In this study identified 20 genera of phytoplankton from five division of the Phytoplankton. Phylum Cyanophyta, with 30 percent of the identified genera that much more constituted. and the phylum Chlorophyta with 25 percent, of Bacillariophyta 20 percent Pyrrophyta 20 percent and Euglenophyta 5 percent had the lowest frequency. Chlorophyta with 25 percent allocated to the division, with 20 percent of Bacillariophyta, with 20 percent of the division; Pyrrophyta Euglenophyta division with 5 percent had the lowest frequency.Euglenophyta phylum was identified as a species. Therefore, based on acquired results, was observred that, vannamie shrimp was reared well using Caspian Sea brakish water in Mazandaran province. In addition, it seems that, vannamei shrimp was gained better results in Mazandaran province compared to other provinces, because of suitable water salinity.
كليدواژه :
درياي خزر , ميگو وانامي , آب لب شور , رشد , بازماندگي , فيتوپلانكتون