Morphometric analysis of anchovy (Engraulis encrasicolus (Linnaeus, 1758)) otoliths in Georgia and Marmara Seas

Abstract

The objective of the study was to examine whether there is a geographical differentiation between the anchovy stocks as well as to carry out otolith morphology and shape analyses work on the otoliths of anchovies caught in Georgia and Marmara. Otoliths obtained from anchovies (<em>Engraulis encrasicolus</em>) caught at two different regions (Georgia and Marmara Sea) were used for otolith morphology and shape analysis in the fishing season of 2011-2012. LAS Image Analysis 3.8 software in MZ75 Leica imaging system was used for biometric measurements and shape analyses of the otoliths. The average lengths of the otoliths were measured to be 2.94±0.263 mm for Georgia anchovy and 2.74±0.123 mm for Marmara anchovy. Additionally, the average widths of the otoliths were measured to be 1.44±0.142 mm and 1.31±0.579 mm for anchovy from Georgia and Marmara, respectively. The shape factor in the otolith shape analyses was measured to be 0.49≤F_F≤0.74 for the Georgia anchovy and 0.55≤F_F≤0.70 for the Marmara anchovy. The roundness factor for Georgia anchovy was determined to be 1.26≤R_D≤1.97 and for the Marmara anchovy it was 1.33≤R_D≤1.69. The length/width ratio was determined to be 1.81≤A_R≤2.28 for Georgia anchovy and between 1.90≤A_R≤2.37 for Marmara anchovy. According to the statistical analyses carried out in the two regions. A_R and F_F values were calculated to be statistically significant (<em>p</em><0.05).