Spawning pattern of Skipjack tuna (Katsuwonus pelamis) in Oman Sea
Document Type : Original Article
Authors
1 Offshore Fisheries Research Center-Chabahar, Iranian Fisheries Science Research Institute, Agricultural Research Education and Extension Organization (AREEO), Chabahar
2 Deputy of Fisheries and Fisheries Ports, Iranian Fisheries Organization, Tehran
Abstract
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.
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