Some biological properties of spiny eel (Mastacembelus mastacembelus, Banks & Solander, 1794) living in the Upper Euphrates River Basin, Turkey.

This study was carried out to determine some bioecological characteristics of Mastacembelus mastacembelus, which is the only species of Mastacembelidae family living in Turkey. Fish samples were caught between 2014-2018 from Keban Dam Lake, one of the most important reservoirs of the upper Euphrates Basin. In totally, 348 Mastacembelus mastacembelus individuals were examined, including 178 males and 170 females. The age distributions were defined between the I-XV age groups. Total lengths ranged from 14.20 to 81.80 cm in males and from 15.60 to 77.30 cm in females. Total length-weight relationships were calculated as W = 0.0083 × TL2.6516 for males, W = 0.0043 × TL2.8310 for females and W = 0.0063 × TL2.7256 for all population, and the growth type was estimated as "negative allometric". The von Bertalanffy growth parameters for all individuals were computed as L∞ = 90.99, k = 0.13, t0 = - 0.45. The total (Z), natural (M), fishing (F) mortality rates and exploitation rate (E) were estimated as Z = 0.313, M = 0.270, F = 0.043 and E = 0.137, respectively. The length at first capture (Lc) was found as 50.72. The optimum, maximum and economic yields were calculated as E0.5 = 0.361; Emax = 0.776; E0.1 = 0.664, respectively.

Some heavy metals in the flesh of chub, Squalius cephalus, from Karakaya Dam Lake (Malatya, Turkey).

This research aimed to find out the levels of Iron (Fe), Zinc (Zn), and Cupper (Cu) in the flesh of Chub (Squalius cephalus) and in the Karakaya Dam Lake water in which they live. The findings were evaluated in terms of the risk of consuming of this fish as human food. In addition, the changes of the heavy metal level of fish with weight, length and sex of them. The accumulation factor for each metal was also found. The level of heavy metals in the flesh of fish were found higher than that in the water. The level of heavy metals changed with the weight, length and sex of fish. The results were compared with acceptable values for heavy metals given by FAO/WHO to detect whether the flesh of chub has any risk for consumption as human food.

Protective role of propolis in chlorpyrifos-induced changes in the haematological parameters and the oxidative/antioxidative status of Cyprinus carpio carpio.

The protective effect of propolis on haematological parameters and antioxidant status were evaluated in the blood and various tissues of carp exposed to chlorpyrifos (CPF). The fish were exposed to sublethal concentrations of CPF (0.040 and 0.080 mg/L) for 10 days, and propolis (10 mg per kg of fish weight) was simultaneously administered. Samples of the blood and tissue (liver, kidney, and gill) were collected at the end of the experiment and analysed for their oxidant-antioxidant status, including the malondialdehyde (MDA) levels, and the superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activity. The samples were also measured for changes in the haematological parameters, such as the red blood cell (RBC) and white blood cell (WBC) counts, the haemoglobin concentration (Hb), the haematocrit (Ht) level, and the erythrocyte indices: the mean corpuscular volume (MCV), the mean corpuscular haemoglobin (MCH) and the mean corpuscular haemoglobin concentration (MCHC). The findings of this study demonstrated that CPF had a negative effect on the haematological parameters and the antioxidant enzyme activities of the fish; this toxic effect was neutralised by the administration of propolis. The present results suggest that propolis can be effective in the protection of CPF-induced toxicity in fish.