Demographic characteristics of Longtail tuna (Thunnus tonggol Bleeker, 1851)in the Persian Gulf and Oman Sea (Hormozgan province)

In this research, trend catch and demographic characteristics and demographic characteristics of Longtail tuna (T.tonggol) were estimated by collecting information from 4 catchment areas on the coast of Hormozgan province including Kang, Salakh, Parsian and Jask. In this project, more than 14000 fish at the research stations were biometric and the growth parameters were infinite length of L∞ = 137 cm, growth factor K = 0.41 (yr-1), natural mortality M= 0.63(yr-1), mortality and mortality (yr-1), F = 0.49, total mortality (yr-1), Z = 1.12 ± 0.16 and exploitation coefficient (yr-1), E = 0.43, and the time zero was -0.26 for the years. Relative production per recruitment, relative biomass per recruitment, exploitation rate and average annual standing stock for kawakawa species were estimated Y '/ Rp =0.03, B' / Rp = 0.36, U= 0.38, respectively. This study showed that this species has moderate vulnerability and medium stock conditions, and also, exploitation ratio of this species stock is under fishing.