Length-Weight Relationship, Condition Factor, and Gonadosomatic Index of Endemic Alburnus istanbulensis (Battalgil, 1941) in Two Different Habitats: Karamenderes River and Bayramiç Reservoir (Çanakkale, Turkey)Nurbanu Partal, Şükran Yalçın Özdilek
Objective: The first aim of this study is to describe the length, weight, condition factor, and GSI of Alburnus istanbulensis (Battalgil, 1941) in two different connected habitats (stream habitat and reservoir lake) in Karamenderes River, Çanakkale. The second aim is to state the growth type of this species in the sampled habitat using the length-weight relationship (LWR) model.
Materials and Methods: The sampling areas are Bayramiç Reservoir and two tributaries on Karamenderes River, which feed the reservoir. Sampling was conducted between May 2016 and June 2017, and depending on the habitat types, different gears were used in the samplings. W=aLb equation was used to calculate the length-weight relationship, K=100×W/L3 equation for the condition factor, and GSI=WG×100/W equation for the gonadosomatic index.
Results: The results showed that the mean fork length of specimens in reservoir and stream habitats were 11.86±1.83 cm and 7.69±3.56 cm, respectively, and body weight of the specimens in the reservoir and stream habitats were 19.28±8.99 g and 8.17±10.82 g, respectively. The condition factor was higher in the reservoir habitat and GSI values were higher in the stream habitats. The growth for all the specimens was positive allometric (b=3.13), whereas in the reservoir habitat the growth was isometric (b=2.99) and in the stream habitat the growth was positive allometric (b=3.12).
Conclusions: Determining the biological characteristics of an endemic species makes an important contribution to the conservation of the species. In the Çanakkale region, data on LWR, growth, condition, and GSI values were not available with the valid name of the species. Therefore, this study is important in terms of presenting new data in the Çanakkale region with the valid name of the species. The findings of this study indicate that the A. istanbulensis species exhibited habitat-dependent differences in LWR, growth, and condition.