2588-5626 5 3 2017 11 22 Spawning pattern of Skipjack tuna (Katsuwonus pelamis) in Oman Sea Spawning pattern of Skipjack tuna (Katsuwonus pelamis) in Oman Sea 111 118 64725 FA Seyed Abbas Hosseini Offshore Fisheries Research Center-Chabahar, Iranian Fisheries Science Research Institute, Agricultural Research Education and Extension Organization (AREEO), Chabahar 0000-0003-3650-2945 Mohammad Reza Mirzaei Offshore Fisheries Research Center-Chabahar, Iranian Fisheries Science Research Institute, Agricultural Research Education and Extension Organization (AREEO), Chabahar Bezhan Azhang Offshore Fisheries Research Center-Chabahar, Iranian Fisheries Science Research Institute, Agricultural Research Education and Extension Organization (AREEO), Chabahar Shiravan Enayati Deputy of Fisheries and Fisheries Ports, Iranian Fisheries Organization, Tehran Journal Article 2018 01 25 In order to determine the spawning pattern, the biometric parameters for Skipjack tuna made from artisanal gillnet fisheries during the years 2007 in Oman Sea along Sistan and Balouchestan coastal waters. The frequency of maturity stages and GSI values obtained from the species showed a long spawning period from November to May, peaking in April-May. Lm50% was obtained as 62.4 for Skipjack tunas, and more than 70 percent of the species was immature when compared with the length frequency of the catches. Sex ratio by size group showed a predominance of males with larger fish. Length-weight relationship by sex showed that in length larger than 61 cm the male accounted for the larger weight. In order to manage the Skipjack resources with aiming at capturing more mature fish, it needs to optimize the mesh sizes of gillnets.    In order to determine the spawning pattern, the biometric parameters for Skipjack tuna made from artisanal gillnet fisheries during the years 2007 in Oman Sea along Sistan and Balouchestan coastal waters. The frequency of maturity stages and GSI values obtained from the species showed a long spawning period from November to May, peaking in April-May. Lm50% was obtained as 62.4 for Skipjack tunas, and more than 70 percent of the species was immature when compared with the length frequency of the catches. Sex ratio by size group showed a predominance of males with larger fish. Length-weight relationship by sex showed that in length larger than 61 cm the male accounted for the larger weight. In order to manage the Skipjack resources with aiming at capturing more mature fish, it needs to optimize the mesh sizes of gillnets.    https://shilsj.ut.ac.ir/article_64725_61cfad6adb7f2bf62aa079ba6d00a9e8.pdf