The "Stock Assessment of Mesopelagic Resources (Myctophids)" project was carried out in the Oman Sea during 15 mounths. In this period, 7 cruises were done and by carrying out 100 hauls, the necessary biological data were collected. It should be mentioned that the studied area was restricted from Rasokuh (57°00' E/25°10'N) in west to Gwatar (61°25'E/25°48'N) in East and water border line of Iran and Oman in South. The Benthosema pterotum was identified as dominant species, This species lives in two different layers, namely D1 (80-130 m) and 02 (250-350 m), during daytime, and before sunset, migrating towards the surface and forms N1 layer. The results show that B. pterotum spawns throughout the year, with 2 peaks, in the end of summer, and end of winter. Myctophids are Zoophague, and Hairtails and Squids, are their main predators......
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