كليدواژه :
تاس ماهي ايراني , فنل , سميّت حاد , هيپرپلازيا
چكيده فارسي :
زمينه و هدف: با توجه به اهميت بوم شناختي و اقتصادي گونه تاس ماهي ايراني به عنوان يك گونه بومي در خطر انقراض ساكن درياي خزر، گستردگي مناطق پراكنش آن و افزايش آلودگي روز افزون آبهاي داخلي به مشتقات نفتي مانند تركيباتي فنلي، بررسي سميت حاد فنل در مرحله جنيني لاروهاي 3 روزه تاس ماهي ايراني ضروري مي باشد.
روش كار: 7تيمار با غلظت هاي 140، 115، 90، 65، 40، 25، 10 ميلي گرم بر ليتر فنل و يك شاهد (هريك 3 تكرار) در نظر گرفته و آزمايشات مربوط به تعيين سميت حاد بر اساس استاندارد O.E.C.D. به صورت ساكن انجام گرفت. در مرحله بعد از سه غلظت زير كشنده فنل (10،25،40 ميلي گرم برليتر) و شاهد در سه تكرار و در شرايط نيمه پايدار براي بررسي اثرات سمي فنل روي آبشش، كبد و كليه به عنوان نشان گرهاي سيتولوژيك در مدت تكامل لارو نورس تا شروع تغذيه فعال استفاده شد. لاروهاي ناهنجار و تلف شده به صورت روزانه جمع آوري و در محلول بوئن فيكس و مراحل آماده سازي بافتي و رنگ آميزي نمونه ها انجام گرديد.
يافته ها: مقدار LC50 طي 96 ساعت فنل 90 ميلي گرم بر ليتر و حداكثر غلظت مجاز فنل براي لاروهاي نورس تاس ماهي ايران 95/1 ميلي گرم برليتر تعيين گرديد. تغييرات بافتي در آبشش پرخوني و هيپرپلازيا در كبد دژنراسيون سلول ها و تجمع ملانين و در كليه اتساع كپسول بومن، شبكه گلومرولي و تخريب توبول ها بودند.
نتيجه گيري: تحقيق حاضر نشان داد كه آلاينده هايي مانند تركيبات فنلي در اكوسيستم هاي آبي بر رشد و نمو لاروهاي نورس تاس ماهي ايراني موثر هستند.
چكيده لاتين :
Inroduction & Objective: Today, the new methods for evaluating the toxic effects of the chemical compounds on the living organisms in fresh and salt water ecosystems was presented. These techniques include molecular, biochemical and cytological methods to study the influence of pollutants were used as biological markers. Survey of the critical toxic of phenol in the embryonic phase of the Persian sturgeon (Acipenserpersicus) is necessary, because of the ecological and economic importance of this fish as an endangered native species on the Caspian sea, the extent of water pollution dispersion and increasing oil derivatives such as phenolic compounds in this sea.Material and Methods:In present study, effects of phenol on Acipenserpersicus on the embryonic 38 phase (3dph) was evaluated. The acute toxicity test for 96h is performed in fully static water condition with aeration .According to OECD standard for evaluating theacutetoxicityofphenol , seven concentrations of phenol (140,115,90,65,40,25,10 mg/l) and control in three replications were used in the static condition .Meanwhile , three concentrations of phenol (40,25,10 mg/l) and control in three replications were used in the semi-static conditionfor surveying the effects of the sublethal concentration's phenol on the gill, liver and kidney as cytological biomarkers during prelarvae period to the beginning activity of feeding.The deformities and mortalities of prelarvae were collected every day and fixed by immersion in Bouin fluid for 24h and then transferred to ethanol 70% .Fish were dehydrated in an ethanol series of ascending concentrations, embedded in paraffin, and serially sectioned at 7 μm thickness on a microtome. The sections weredried for 24h and stained with H & E. Results: Maximum Allowable Toxicant Concentration of phenol for relarvae's Acipenserpersicus was 1.95 mg/l. Histopathological changes in the gill, liver, kidney werenoticed. The histological alterations were found in the sections including blood congestion and hyperplasia in the gills, cellular atrophy, nuclear degeneration and melanine aggregates in the liver, tubular degeneration, dilation glomerular capillaries and interstitial spaces degeneration in the kidney .Conclusion:In conclusion , the present study was showed that the concentration of pollutants like phenol compounds in the aquatic ecosystems effects on the development of the prelarvae's Persian sturgeon, thus it is essential to enhance our knowledge on toxic effects of the pollutants on the endangered species like Persian sturgeon.
