Cadmium bioaccumulation and depuration by freshwater Crayfish, Astacus leptodactylus

Özet

Tatlı su kereviti Astacus leptodactylus (Eschscholtz 1823), Türkiye’nin birçok göl ve akarsuyunda doağl olarak yayılım gösterir. Omnivor olan kerevitler çeşitli besin kaynaklarında kullanabilirler ve buna bağlı olarak kirleticilerden etkilenirler. Kerevitler eko toksikolojide, omurgasızlar için mükemmel bir modeldir. Bu çalışmda kadmiyum farklı doku ve organlarında kadmiyum birikimi ve atılımı göstermiştir. Kerevitler statik deney koşullarında 3 hatfa boyunca 0,1, 0,5 ve 1,0 mg Cd/L maruz bırakılmış ve 7, 14, 21 günün sonunda hepatopankreas, solungaç, dış iskelet ve abdominal kaslarda kadmiyum birikimi belirlenmemiştir. Birikimin sırasıyla hepatopankreas>solungaç>dış iskelet>abdominal kaslarda 118,33, 661,63, 39,47 ve 3,77 mg/L olduğu bulunmuştur. Çalışmanın sonunda kerevitin kadmiyum hızla eliminine ettiği (atıldığı) sonucuna varılmıştır.

Abstract

The freshwater crayfish Astacus leptodactylus (Eschscholtz 1823) is naturally and widely distributed in the lakes, ponds and rivers throughout Turkey. They are omnivorous and thus are open to toxicant exposure from a variety of sources including the water column, adsorbed onto foodstuff, by bioaccumulation prey. Crayfish can serve as an excellent model species to increase the knowledge base for invertebrate ecotoxicology. Cadmium bioaccumulation and depuration in the various tissues of the crayfish Astacus leptodactylus were investigated. Adult specimens were exposed to 0.1, 0.5, and 1.0 mg Cd/L under static conditions for three weeks. At the end of the 3rd week, the specimens were divided into three groups and transferred into dechlorinated water for either 1, 2 or 3 weeks for depuration. After 7, 14, and 21 days, four crayfish from each group were sacrificed and were dissected into their hepatopancreas, gill, abdominal muscle and exoskeleton tissues for evaluation of Cd accumulation. The following accumulation pattern was obtained in decreasing order; hepatopancreas>gills>exoskeleton>abdominal muscles with values of 118.33, 661.63, 39.47, and 3.77 mg/L, respectively. Based on the present work we have concluded that crayfish have a great potential for rapid accumulation and depuration of Cd in fresh water.