Inter-population morphological variability of the round sardinella (Sardinella aurita Valenciennes, 1847) in the Algerian Coast based on body morphometric, meristic and otolith shape

Several studies on the round sardinella, Sardinella aurita (Valenciennes, 1847) have focused on the identification of stock composition and boundaries, using one method of discrimination. In this study, three approaches (body morphometric, meristic character (vertebrae number) and otolith shape) were applied on the population of round sardinella along the Algerian Coast in the Mediterranean Sea in order to obtain useful information for the management of this resource. 627 specimens were collected from nine locations from December 2018 to January 2019. The linear discriminant analysis (LDA) applied on both body morphometric characters and the otolith shape which indicated significant difference between areas with a low rate of classification success (47% for body morphometric analysis and 37.5% for otolith shape analysis), the misclassification percentage for each sampling location was explained by the proximity of the sites. Grouping samples into three regions according the Algerian coastline division reduced the misclassification rate; the overall random assignment of individuals into their original sample obtained by LDA was 70% for the morphometric characters, and 55% for the otolith shape. However, no significant difference was found between areas using the analysis of the number of vertebrae. No significant sexual effects were observed on the body morphometric characters, on the otolith shape and on the number of vertebrae.