Length-Weight Relationships of Five Fish Species from the Sakarya River, Turkey

Abstract

Aims: The study aimed to investigate the length-weight relationships for five fish species (Capoeta baliki, Capoeta sieboldii, Squalius cephalus, Silurus glanis and Esox lucius). Place and Duration of Study: Samples were caught by trammel nets from the Sakarya River, in the northwestern region of Turkey, between October 2010 and February 2012. Methodology: Fish samples were obtained by trammel nets (inner mesh sizes 32, 36, 40, 44, and 48 mm nominal bar length). Scientific names for each species were checked with the Catalog of Fishes [34]. Total length (TL) was measured to the nearest centimeter (cm) and body weight (W) was recorded in nearest gram (g). All length-weight relationships for five species were calculated using the equation W=a Lb [35]. The coefficients obtained were analyzed with ANOVA. The Student’s t-test was used for comparison of the slopes [36]. Furthermore, the physical and chemical characteristics of the studied area were monitored. Results: A total of 1197 fish samples were collected in this survey. Five fish species belonging to three families, Cyprinidae (90.64%), Siluridae (5.35%), and Esocidae (4.01%), were examined. Estimates for parameter b of the length-weight relationship ranged between 2.444 and 3.222. There was no significant difference in b-value for S. cephalus (P>0.05). In contrast, the b-values of the other species were significantly different from each other (P<0.05). The growth type of S. cephalus and S. glanis was determined as positive allometry (b>3), whereas C. baliki, C. sieboldii and E. lucius showed negative allometry (b<3). Conclusion: In this study, a large number of C. baliki specimens were examined for the first time. In addition, it was determined that the parameters of length-weight relationships for all studied species were substantially different from each other.