Tr en Bu çalışmada, Keban Baraj Gölü’nde yaşayan Barbus grypus Heckel, 1843 populasyonuna ait toplam 90 örnekte sagittal otolit büyüklüğü (uzunluk, genişlik ve ağırlık) ile balık boyu (total boy) arasındaki ilişkiler incelendi. Otolitlerin uzunluğu, genişliği ve ağırlığı sırasıyla (minimum-maksimum ±standart sapma), 2,56-3,76 ±0,22 mm, 1,66-2,56 ±0,18 mm ve 5,2-12,5 ±1,27 mg arasında tespit edildi. Balıkların total boyları ise 377-699 ±53,5 mm arasında belirlendi. Ayrıca, otolit büyüklüğü ile total boy arasında pozitif yönde yüksek korelasyon tespit edildi. In this study, the relationships between total fish length and sagittal otolith size (length, width and weight) of a total 90 specimens belonging to the population of Barbus grypus Heckel, 1843 inhabiting Keban Dam Lake were examined. The otolith lengths, widths and weights (minimum-maximum ±standard deviation) were determined as 2.56-3.76 ±0.22 mm, 1.66-2.56 ±0.18 mm and 5.2-12.5 ±1.27 mg, respectively. Total lengths of the fishes were found as 377-699 ±53.5 mm. In addition, a high positive linear correlation was detected between the otolith size and total length of fishes.

In this study, the concentrations of some heavy metals were determined in the muscle of Luciobarbus esocinus Heckel, 1843 and in water where they live. The results were evaluated in term of potential human risk of consumption of this fish and the relationship between the heavy metal load of fish and some of their biological aspects (weight, length and sex). In addition, the accumulation factor of heavy metals in the muscle of L. esocinus were also determined. The Cr, Pb and Ni were not found in detectable levels according to results obtained by ICP. Only Cu, Zn and Fe were detected. It was found that heavy metals concentrations in the muscle of L. esocinus were higher than that in the water. The concentration of heavy metals showed differences according to weight, length and sex of fish. The results were discussed and compared with tolerable values for heavy metals provided from the EPA, FAO and WHO in order to determine whether this fish species has any risk for human consumption.

In this study, the accumulation of some heavy metals in spiny eel (Mastacembelus mastacembelus Banks and Solander, 1794) living in Karakaya Dam Lake was determined and human health risk of this fish when consumed as food was examined. For this purpose, the amounts of copper (Cu), chromium (Cr), cadmium(Cd), iron (Fe), zinc (Zn) in water samples and in the muscle tissues of the fishes were determined. The amounts of heavy metals showed differences in the muscle tissues of Mastacembelus mastacembelus according to weight, length, sex and age groups of fish. In conclusion the amounts of heavy metals in the flesh of spiny eels were found lower than that recommended by EPA, WHO, FAO and TFC.

The main contributor to Türkiye’s abundant freshwater fish biodiversity is its geographic location. This fauna consists of endemic, native, and non-native fish species. The introduction of Gambusia holbrooki Girard, 1859 to Lake Amik in the 1920s for the biological control of malaria was the first introduction of nonnative species to Türkiye. Atherina boyeri Risso, 1810 and other nonnative fish species have recently been introduced to Türkiye’s freshwaters. In this research, the first records of invasive Gambusia holbrooki (Keban Dam Lake, in Elazığ Province) and Atherina boyeri (Karakaya Dam Lake, in Elazığ Province) are cited from the Upper Euphrates River Basin in the Eastern Anatolia Region of Türkiye. In situ electrofishing equipment was used to gather the specimens. Fish muscle samples were used to extract genomic DNA, which was then used to barcode the mitochondrial cytochrome c oxidase subunit I (COI) gene to identify different species of fish. The identification of invasive fish species using DNA barcoding is an effective technique, as evidenced by the comparison of amplified COI sequences to the BLAST database.