Length–weight, length–length relationships and condition factors were estimated for two fish species (Chondrostoma regium, Barbus lacerta) caught between October 2014 and September 2015 in the 14 distinct locations of Karasu River, East Anatolia, Turkey. Minimum and maximum total length and weight were observed at 7.5 to 31.0 cm and from 5.7 to 280 g for C. regium, 7.0 to 24.0 cm and from 4.0-211 g for B. lacerta. The b values determined as 2.77 for Chondrostoma regium; 3.10 for Barbus lacerta. The types of growth were found negative allometric for C. regium and isometric growth for B. lacerta. The length-length relations between total, fork, and standard lengths for the two fish species were highly significant. The relative condition factor values were found to 1.102±0.013 for C. regium; 1.176±0.019 for B. lacerta. This study submits for the first time LWR, LLR and condition factor of two species in the Karasu River.

In this study, length-weight relationship (LWR), length- length relationship (LLR) and condition factor (K) of Angora loach, Oxynoemacheilus angorae were determined. A total of 103 specimens were sampled from Kılıçözü Stream in 2014. The length and weight of specimens were ranged 3.5-9.8 cm and 0.38-6.58 g, respectively. Length-weight relationships for female, male and all samples were found as W= 0.01056.TL2.896 (r²= 0.923), W= 0.00963.TL2.940 (r²= 0.978) and W= 0.00987.TL2.929 (r²= 0.963), respectively. LWRs indicated an isometric growth in female, male and all samples. The values of Fulton’s condition factor (K) ranged from 0.699 to 1.246 for females and from 0.654 to 1.072 for males. All length-length relationships were statistically significant.