en Stock assessment Stock assessment پژوهشي Orginal research papers <p style="margin: 0px 0px 11px; line-height: 200%;">The aim of the present study was to estimate the population parameters including length-weight relationship (LWR), condition factor (KF), relation condition factor (K_n), age, growth and mortality of <em>Alburnus</em><em> mossulensis</em> in Azad dam and Komasi River in Kordestan Province, Iran. Of 522 specimens, the fork length, total length and weight of <em>A. </em><em>mossulensis </em>ranged from 70 to 164, 75-175 mm, and 4.3 to 48.1 g and averaged (&plusmn;SD) 114.0 (&plusmn;15.97), 127.5 (&plusmn;25.29) mm and 18.2 (&plusmn;5.61) g, respectively. The length-weight regression was W=0.0003&times;FL^2.7434 indicating a negative allometric growth. The sex ratio (M:F) was 1:0.49, for adult <em>A. </em><em>mossulensis</em> (n=134) which differed significantly from the expected 1:1 ratio (<em>p</em><0.001). The von Bertalanffy growth parameters were estimated as <em>L</em>_&infin;=170.3 mm, <em>K</em>=0.46 yr^-1, <em>t</em>₀=-0.59 yr. The instantaneous coefficient of natural mortality was estimated as 0.85 yr^-1. The average of condition factor (KF) was 1.27(&plusmn;0.161). Statistically significant differences were found in KF during different seasons (<em>p</em><0.001). There was a significantly negative correlation between FL and KF (r²=0.60). The average of relative condition factor (K_n) was 1.06&plusmn;(0.130). In the present study, the K_n of <em>A. mossulensis</em> were close to 1 and greater than 1 in Komasi River and reservoir, respectively. These results suggested the well-being of the fish was good in Azad Dam region.&nbsp;</p> Age, Growth, Condition factor, Alburnus mossulensis, Azad Dam, Kordestan 672 683 http://jifro.ir/browse.php?a_code=A-10-120-2&slc_lang=en&sid=1 H Fazli hn_fazli@yahoo.com 100319475328460030910 100319475328460030910 Yes Caspian Sea Ecology Research Center G.R Daryanabard daryanabard@yahoo.com 100319475328460030911 100319475328460030911 No Caspian Sea Ecology Research Center A Janbaz aliasgharjanbaz@yahoo.com 100319475328460030912 100319475328460030912 No Caspian Sea Ecology Research Center M Naderi Jolodar naderi_j@yahoo.com 100319475328460030913 100319475328460030913 No Caspian Sea Ecology Research Center R Mirzaei ? 100319475328460030914 100319475328460030914 No Jihad-Agriculture of Kurdistan Organization H Hoseinpour ? 100319475328460030915 100319475328460030915 No Jihad-Agriculture of Kurdistan Organization N Vahedi ? 100319475328460030916 100319475328460030916 No Jihad-Agriculture of Kurdistan Organization