Determination of Acute and Chronic Toxic Effects of Methyl Parathion on Inci Kefali (Chalcalburnus Tarichi Pallas, 1811)

Abstract

Bu çalışmada Van Gölü Havzasında en fazla kullanılan pestisitlerden olan metil paration (MP)'un havza için endemik ve ekonomik öneme sahip olan inci kefali (Chalcalburnus tarichi)'nde akut ve kronik toksik etkileri araştırıldı. Akut denemede, 6.45-15.00 mg/L arasında 9 farklı MP konsantrasyonu uygulandı. MP'nin bütün konsantrasyonlarında balıklarda davranış bozuklukları gözlendi. İlk tepki 15.00 mg/L konsantrasyonda uygulamadan 2 saat 10 dakika sonra, ilk ölüm 13.50 mg/L konsantrasyonda uygulamadan 3 saat 45 dakika sonra gözlendi. Letal konsantrasyon 7.97 mg/L, 96 saat LC50 değeri 11.44 mg/L, 96 saat EC50 değeri 6.89 mg/L ve LT50 değeri 28.14-289.29 saat arasında belirlendi.Kronik denemede hemoglobin ve hematokrit değerlerinin 2.10, 4.28 ve 6.11 mg/L konsantrasyonlarda azaldığı (P<0.05), eritrosit sayısı, ortalama eritrosit hacmi ve eritrosit başına düşen ortalama hemoglobin miktarı değerlerinin değişmediği belirlendi. MP'nin kan hemoglobin ve hematokrit değerleri esas alınarak LOEC 2.10 mg/L, NOEC 1.47 mg/L, MATC 1.76 mg/L, ACR 6.50 mg/L olarak belirlendi.MP'nin 4.28 mg/L konsantrasyonunda karaciğer hücrelerinde yağ birikimi, damarlarda genişleme ve genellikle damar etrafında lokal nekroz, sarı damlalar ve eozinofilik hücre gruplarının varlığı gözlendi. Solungaç yapılarında primer lamella epitelinde kalınlaşma ve sekonder lamellerin uç kısmında kıvrılma ve epitel tabakada kopmalar belirlendi. Ovaryumlarda herhangi bir histopatolojik bulguya rastlanmazken testislerde kanlanmalar, özellikle mitotik safhadaki üreme hücrelerinde bozulmalar, folikül lumeninde genişleme gözlenirken mitotik safhaya girmeyen testiste intersititiyal dokuda eozinofilik hücre gruplarının varlığı gözlendi.Karaciğer ve kas dokusunda asetilkolinesteraz (AChE) aktivitesinin değişmediği bununla birlikte beyin dokusunda azaldığı (P<0.05), butirilkolinesteraz (BChE) aktivitesinin ölçülen dokularda değişmediği belirlendi.Sonuç olarak MP inci kefali için bazı morfolojik, histolojik, hematolojik ve biyokimyasal kriterlere göre akut ve kronik toksik bir maddedir. Türün yaşadığı tatlısu ortamlarında MP konsantrasyonu 0.1144 mg/L'yi geçmemeli, MP tarımda kontrollü olarak kullanılmalıdır.Anahtar Kelimeler: İnci Kefali, Chalcalburnus tarichi, Metil paration, Akut toksisite, Kronik toksisite, Hematoloji, Histopatoloji, AChE, BChE, Ekotoksikoloji, LC50

In this study, acute and chronic toxic effects of methyl parathion (MP), one of the most common used pesticides in Lake Van Basin, on Chalcalburnus tarichi having economic importance endemic and in the basin were studied. In the acute experiment, 9 different MP concentrations (6.45-15.00 mg/L) were applied. Behavior disorders in fish were observed in all MP concentrations. First response was observed in 130 minutes after the application of 15.00 mg/L, and first mortality was observed in 225 minutes after the application of 13.50 mg/L. It was determined that the lethal concentration was 7.97 mg/L; 96 hours LC50 value was 11.44 mg/L; 96 hours EC50 value was 6.89 mg/L; LT50 value was between 28.14 to 289.29 hours.In the chronic experiment, it was determined that hemoglobin and hematocrite values significantly (P<0.05) decreased at 2.10, 4.28, and 6.11 mg/L concentrations of MP, while erythrocyte number, mean erythrocyte volume, and mean hemoglobin amount per erythrocyte were not changed. In fish blood MP applied, LOEC, NOEC, MATC, and ACR values of hemoglobin and hematocrit were found 2.10 mg/L, 1.47 mg/L, 1.76 mg/L, and 6.50 mg/L, respectively.In 4.28 mg/L concentration of MP, fat accumulation, vessel expansion, local necrosis around the vessels, yellow droplets, and existence of eosinophilic cells groups in liver cells were observed. In gill structures, primer lamella epithelium was widened, seconder lamella?s tips was curled, and epithelium layer was broken by MP applications. Although there was no histopathological symptoms in ovariums, there was hemorrhagies in testis, especially disorders in reproduction cells in mitotic stage, there was wideness in folicule lumen, and there was an existence of eosinophilic cell groups in intersititial tissue in non-mitotic testis by comparing the controls.It was also determined that there was no difference in acetylcholinesterase (AChE) activity in liver and muscle tissues, but it significantly (P<0.05) decreased in brain tissue. However, butyrylcholinesterase BChE activity did not change any of the mentioned tissues.In conclusion, MP is a acute and chronic toxic material for Chalcalburnus tarichi based on the results of this researchs on some morphological, histhological, hematological, and biochemical parameters. In the freshwater environments living this species, MP concentration should not exceed 0.1144 mg/L and MP should be used in controlled in agriculture.Key Words: Chalcalburnus tarichi, Methyl parathion, Acute toxicity, Chronic toxicity, Hematology, Histopathology, AChE, BChE, Ecotoxicity