Morphometric analysis of anchovy (Engraulis encrasicolus Linnaeus, ۱۷۵۸) otoliths in Georgia and Marmara Seas

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 (Engraulis encrasicolus) caught at two different regions (Georgia and Marmara Sea) were used for otolith morphology and shape analysis in the fishing season of ۲۰۱۱-۲۰۱۲. LAS Image Analysis ۳.۸ software in MZ۷۵ Leica imaging system was used for biometric measurements and shape analyses of the otoliths. The average lengths of the otoliths were measured to be ۲.۹۴±۰.۲۶۳ mm for Georgia anchovy and ۲.۷۴±۰.۱۲۳ mm for Marmara anchovy. Additionally, the average widths of the otoliths were measured to be ۱.۴۴±۰.۱۴۲ mm and ۱.۳۱±۰.۵۷۹ mm for anchovy from Georgia and Marmara, respectively. The shape factor in the otolith shape analyses was measured to be ۰.۴۹≤FF≤۰.۷۴ for the Georgia anchovy and ۰.۵۵≤FF≤۰.۷۰ for the Marmara anchovy. The roundness factor for Georgia anchovy was determined to be ۱.۲۶≤RD≤۱.۹۷ and for the Marmara anchovy it was ۱.۳۳≤RD≤۱.۶۹. The length/width ratio was determined to be ۱.۸۱≤AR≤۲.۲۸ for Georgia anchovy and between ۱.۹۰≤AR≤۲.۳۷ for Marmara anchovy. According to the statistical analyses carried out in the two regions. AR and FF values were calculated to be statistically significant (p<۰.۰۵).

Keywords:

Engraulis encrasicolus , Otolith , Morphometric measurements , Shape analyses , AR , FF , and RD