en Biology & physiology Biology & physiology پژوهشي Orginal research papers <font face="Times New Roman" size="3"> </font><p class="MsoNormal" style="margin: 0cm 0cm 0pt text-align: justify line-height: 150% unicode-bidi: embed direction: ltr text-justify: kashida text-kashida: 0%"><font face="Times New Roman"><font size="1"><span style="mso-bidi-language: AR-SA">Traditional morphometric measurements and meristic counts were used to investigate the hypothesis of population fragmentation of </span><i>Mash mahi</i>,<i> Aspius aspius taeniatus</i> (Eichwald, 1831)<span style="mso-bidi-language: AR-SA"> among two fishing areas </span>in southern Caspian Sea basin(Tonekabon:32 specimens <span style="mso-spacerun: yes"> </span>and Sari:34 specimens ). Univariate analysis of variance showed significant differences between the means of the two groups for <span style="mso-bidi-language: AR-SA">12 out of 26 standardized morphometric measurement and three out of nine meristic counts. </span>In discriminant function analysis (DFA)<span style="mso-bidi-language: AR-SA">, the proportion of individuals correctly classified into their original groups was 82.1% and 61.2% for morphometric and meristic characteristics, respectively. Clustering based on Euclidean distances among groups of centroids using an UPGMA and also principal component analysis’ results (PCA) for morphometric and meristic data indicated that two samples of <i>Mash mahi</i> were distinct from each other in these regions, while there were a relatively high degree of overlap between two locations. </span><b style="mso-bidi-font-weight: normal"><i style="mso-bidi-font-style: normal"><o:p /></i></b></font></font></p><font face="Times New Roman" size="3"> </font> Aspius aspius taeniatus, Morphometric, Meristic, Caspian Sea, population differentiation. 627 643 http://jifro.ir/browse.php?a_code=A-10-1-185&slc_lang=en&sid=1 E. Rezaei e_re205@yahoo.com 10031947532846004826 10031947532846004826 Yes S. Vatandoust 10031947532846004827 10031947532846004827 No M. kazemian 10031947532846004828 10031947532846004828 No H. Anvarifar 10031947532846004829 10031947532846004829 No