en Biology & physiology Biology & physiology پژوهشي Orginal research papers <p>  Estimates of age, growth parameters, length-weight relationship and length and age at first maturity of the <i>otolithes ruber</i> are required for fishery management. We used counting annuli on the section of sagittal otoliths to age <i>O.ruber </i>from the Northwest Persian Gulf in south of Iran. Estimated ages ranged from 0 to 6 years, and maximum frequency of fishes was observed in age-group 1. The values of growth parameters L_∞, k and t_o were calculated by von Bertalanffy model and the results were 67.57 (cm), 0.27 (year^-1) and -0.43 respectively. Parameters b and an in length-weight relationship were calculated 3.19 and 0.005 respectively. Length and age at first maturity were estimated 28 cm and 1.55 year. </p> Otolithes ruber, Age composition, Growth, Length at first maturity, Persian Gulf 13 27 http://jifro.ir/browse.php?a_code=A-10-1-133&slc_lang=en&sid=1 Gh. Eskandari g_eskandary@yahoo.com 10031947532846002648 10031947532846002648 Yes A. Savari 10031947532846002649 10031947532846002649 No P. Kochanian 10031947532846002650 10031947532846002650 No A. Taghavi Motlagh 10031947532846002651 10031947532846002651 No