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Temporal Changes in Concentrations of Some Trace Elements in Muscle Tissue of Crayfish, Astacus leptodactylus (Eschscholtz, 1823), from Keban Dam Lake

Crayfish (Astacus leptodactylus Eschscholtz, 1823) is the native crayfish species in Turkey. It was exported regularly to Western Europe. In this study, bioaccumulation and temporal trends of some trace elements (arsenic: As, cadmium: Cd, copper: Cu, mercury: Hg, lead: Pb, and zinc: Zn) in edible abdomen muscle of crayfish from Keban Dam Lake (Elazığ, Turkey) were investigated for the 2006–2012 period. Sequence of metal concentration levels was Zn > Cu > Hg > Pb > Cd > As in muscle tissues. The highest concentration of Zn (21.69 mg kg−1) was detected in 2006, while the lowest (4.35 mg kg−1) in 2009. In general, it was found that the concentrations of trace elements investigated were lower than the maximum permissible limits of the food regulations of the Ministry of Food, Agriculture, and Livestock (MFAL), the Turkish Food Codex and Commission Regulation (EC). If the crayfish selected for the study are recognized as bioindicators of environmental pollution, then it is possible to conclude that the changes in studied trace elements concentrations in the Keban Dam Lake are being steady.

Oksijen Radikal Absorbans Kapasitesi (ORAK) Seviyeleri Farklı Bitki Masere Yağlarının Yoğun Stoklanmış Gökkuşağı Alabalıklarının (Oncorhynchus mykiss) Bazı Kan Parametrelerine Etkileri

Bu calismada, oksijen radikal absorbans kapasiteleri (ORAK) farkli bitkilerin [sogan (Allium cepa), sarimsak (Allium sativum), reyhan (Ocimum basilicum), hashas (Papaver somniferum), zencefil (Zingiber officinale), zerdecal (Curcuma longa)], masere yaglari elde edilmistir. Calisma, kontrol grubu (aycicek yagi) dahil olmak uzere toplam 7 grupta, bir hafta boyunca 30 litrelik havlandirmali tanklarda, su sirkulasyonu olmadan gerceklestirilmistir. Her tanka 20 adet (14,6±1,0 gr) gokkusagi alabaligi yuksek yogunlukta stoklanmistir. Masere yaglar, ilk gun baligin lateral cizgisi boyunca derisine surulmustur. Masere yaglarin su ve balik uzerine etkilerini belirlemek icin suyun Oksidasyon-reduksiyon potansiyeli (ORP) ve gokkusagi alabaliklarinin hematolojik parametreleri [granulosit (GRAN), beyaz kan hucresi (WBC), kirmizi kan hucresi (RBC), hemoglobin (HGB), kirmizi kan hucresindeki ortalama hemoglobin miktari (MCH), eritrositlerin hacmindeki degisikligin standart sapmasi (RDW-SD), trombositlerin ortalama buyuklugu (MPV), kan hucrelerindeki trombositlerin dagilim araligi (PDW), buyuk hucreli trombosit orani (P-LCR)] baliklarda incelenmistir. Sonuclar suyun ORP seviyesinde azalmalar oldugunu gostermistir. En yuksek yasama orani hashas yagi uygulamasinda oldugu belirlenmistir. 7 gunluk uygulama sonunda, en yuksek WBC, LYM, HGB, MCV, MCH, MPV degerleri zencefil yagi uygulamasinda (ORAK: 28.811) belirlenmistir. En yuksek RBC degeri zerdecal yagi (ORAK: 159.277) uygulamasinda, en yuksek GRAN degeri hashas yagi (ORAK: 481) uygulamasinda, en yuksek HCT ve PLT degerleri reyhan yagi (ORAK: 67.553) uygulamasinda oldugu tespit edilmistir. Calisma sonunda masere yaglarin deriye surulmesinin kan parametrelerini uyardigi tespit edilmistir.

Biochemical impacts of the textile dyes Remazol Brillant Blue R and Congo Red on the crayfish Astacus leptodactylus (Decapoda, Astacidae)

In this study, we determined the effects of the textile dyes Remazol Brillant Blue R (RBBR) and Congo Red (CR) on the enzymatic activities of Glutathione S-Transferase (GST), cytochrome P450 (CYP1A1) and Lactate dehydrogenase (LDH), in hepatopancreas of Astacus leptodactylus . The crayfishes were exposed to 0.5, 1.0, and 2.0 mg/l of RBBR or CR, for 24 and 48 h. The recorded GST activity clearly increased after 24 or 48 h exposure to CR, compared to a control group (p 0.05). The activity of CYP1A1 generally decreased, but LDH activity increased in the groups exposed to different doses of CR and RBBR, when compared to their control groups. Detoxification enzymes (as GST, and CYP1A1) and metabolic enzymes (as LDH) can be proven to make useful markers for further evaluating the physiological effects of CR and RBBR on crayfish.

Influence of stock density on digestive enzyme activity (trypsin), heat shock protein 70 (HSP70), and oxidative stress biomarkers of narrow clawed crayfish, Astacus leptodactylus Eschscholtz, 1823 (Decapoda, Astacidae)

Stocking density causes changes in behaviour and physiology of aquatic animals and high density can cause oxidative damage in living cells. Therefore, experiments were designed to investigate the effects of stocking density on the oxidant-antioxidant response (glutathione (GSH), glutathione peroxidase (GSH-Px), catalase (CAT), and malondialdehyde (MDA)), digestive enzyme activity (trypsin), and heat shock protein 70 (HSP70) of narrow clawed crayfish ( Astacus leptodactylus ). The experiment was conducted to assess effects by stocking 3, 6, 9 and 12 crayfish/m 2 . Crayfish were stocked into 12 fiberglass tanks, three replicates per treatment and fed for 45 days. Our results indicated that activity of GSH-Px, MDA, and GSH levels increased in hepatopancreas (p<0.05) and muscle tissues (p<0.05) with increasing stock concentration while CAT activity decreased (p<0.05). Trypsin and HSP70 insignificantly increased in haemolymph. In conclusion, oxidative stress biomarkers were negatively influenced by increased quantitative changes in stocking density.