Length-Weight (L-W), Length-Length (L-L) Relationships and Condition Factor of Gobio artvinicus (Teleostei : Gobionidae) from the Lower Çoruh River Basin, NE Türkiye

Abstract

In this study, some basic biological parameters (e.g. sex ratio, condition factor, LWRs and LLRs) of G. artvinicus (Artvin gudgeon) inhabiting Borçka Reservoir and its tributaries from the lower Çoruh River Basin were investigated for the first time. Fish specimens were collected from June 2017 to May 2018 and totally 120 Artvin gudgeon (65 females and 55 males) ranging from 8.1 cm to 13.2 cm in TL were sampled. The sex ratio (F:M) was calculated as 1.18:1.00 in favour of females, but did not deviate from the expected ratio of 1:1 (χ²=0.834, P˃0.05). The total length-weight relationships were determined as W= 0.008TL3.159 (r2=0.971, P˃0.05) for females, as W= 0.012TL2.971 (r2=0.980, P˂0.05) for males and as W= 0.009TL3.088 (r2=0.970, P˃0.05) for all individuals. While the b-values which reflect the body shape were significantly different from the isometric growth indicating positive allometric growth for females and all individuals (Pauly’s t- test, P˂0.05). however, the b value of males did not differ from the isometric growth (b=3) pattern (Pauly’s t- test, P˂0.05). The slopes (b values) were found statistically significant for both sexes (ANCOVA, P 0.9) for each sex and relationship. Mean Fulton's condition factor values were calculated as 1.128±0.011 for females and 1.102±0.008 for males indicating a good growth condition in this habitat. The present study will provide a baseline on some biological parameters of G. artvinicus to provide a guideline for the fisheries management authority and fisheries scientists for further investigations as well as presents the first known reference on the LWRs and LLRs of this species for the FishBase database. Furthermore, the reported results will contribute to the conservation and sustainability of this species in the area.