en Biology & physiology Biology & physiology پژوهشي Orginal research papers <span style="font-size:11pt"><span style="line-height:120%"><span style="text-autospace:none"><span style="font-family:Calibri,sans-serif"><span lang="TR" style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black">Reproduction and spawning patterns of the Yellowtail scad (<i>Atule mate</i>) were studied in the Persian Gulf and Oman Sea (Hormozgan coastal waters) from December 2016 to November 2017. A total of 447 fish were collected from Bandar Lengeh, Qeshm Island, Bandar Abbas, and Bandar Jask landing sites. Minimum and maximum fork lengths of this species were 10 and 33 cm, with average</span></span></span></span> <span lang="TR" style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black">20.63&plusmn;1.73 cm. The total weight ranged from 12.9 to 363.2 g, with average</span></span></span></span> <span lang="TR" style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black">113.08&plusmn;31.69g. The relationship between length and weight was obtained as W=0.017L ^2.89(R²=0.92) which showed that the fish has an isometric growth. Monthly analysis of the reproductive stages and gonadosomatic index showed that reproductive cycle beginning in January and continued with a sharp decreasing trend from March. The mean length at first maturity (L_m50%) for female was 19.8 cm. The sex ratio </span></span></span></span><span dir="RTL" lang="AR-SA" style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black">)</span></span></span></span><span lang="TR" style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black">F:M) was 1.5:1.</span></span></span></span></span></span></span></span> Atule mate, Spawning, Gonadosomatic Index, Sex ratio, Persian Gulf, Oman Sea, Lm50% 640 649 http://jifro.ir/browse.php?a_code=A-10-4305-1&slc_lang=en&sid=1 A. Najafi Nasab asgharnajafi1347@gmail.com 100319475328460046360 100319475328460046360 No Trainer University E. Kamrani eza47@yahoo.com 100319475328460046361 100319475328460046361 Yes Hormozgan University, Bandar Abbas, Iran F. Kaymaram farhadkaymaram@gmail.com 100319475328460046362 100319475328460046362 No Tehran University of Research Sciences M.R. Fatemi reza_fatemi@hotmail.com 100319475328460046363 100319475328460046363 No Tehran University of Research Sciences E. Ramezani Fard eranazanifard@gmail.com 100319475328460046364 100319475328460046364 No Tehran University of Research Sciences