en Ecology Ecology پژوهشي Orginal research papers <p>The Length-Weight Relationship (LWR) and condition factors (CF) of 10441 the oriental river prawn <em>Macrobrachium nipponense </em>collected from Anzali lagoon from March to December 2015 were studied. Length, weight and other external features of all specimens were measured. The Total length and body weight of <em>M. nipponense </em>ranged from 12.3-97 mm and 0.1-11.7 g respectively. A strong positive relationship was observed between the shrimp length and weight in both sexes (r= 0.95). There were significant differences in the condition factors of males and females (p < 0.05). The lowest CF value was observed in station 1 (CF= 1.28 &plusmn; 0.04) and the highest in station 2 (CF= 1.38 &plusmn; 0.34). In this study the regression coefficient (b) was lower than 3.0 for females and 3 for males, and combined sexes which was reflecting allometric growth of the <em>M. nipponense</em>.</p> Length-weight relationship (LWR), Condition factor (CF), Macrobrachium nipponense, Anzali lagoon. 496 500 http://jifro.ir/browse.php?a_code=A-10-2538-1&slc_lang=en&sid=1 A.A. Khanipour aakhanipour@yahoo.com 100319475328460032515 100319475328460032515 No Agricultural Research Education and Extention Organization (AREEO), Anzali A. Noori nooryahmad@gmail.com 100319475328460032516 100319475328460032516 Yes University of Hormozgan M. Amini Mehrnush.amini@gmail.com 100319475328460032517 100319475328460032517 No University of Hormozgan E. Kamrani ezas47@gmail.com 100319475328460032518 100319475328460032518 No University of Hormozgan