Age and Growth of Southern Bluefin Tuna, Thunnus maccoyii, Based on Otolith Microstructure

Abstract Age and growth of southern bluefin tuna (SBT, Thunnus maccoyii ) were estimated based on otoliths collected by Korean longline vessels in the Atlantic Indian Oceans from 2015 to 2019. A total 739 specimens used estimate age SBT, with sizes ranging 66 181 cm fork length. It was confirmed that otolith is a suitable aging characteristic for determining SBT age, annuli can be as an annual ring. The relationship between length (FL) weight ( W = 7.7e − 05FL 2.722 R 2 0.874). von Bertalanffy’s parameters non-linear method using length-at-age data L ∞ 170.0 cm, K 0.200/year, t 0 1.615 years, 95% confidence intervals 166 175 , 0.17–0.23/year 2.27 1.09 years bootstrapping. Kimura’s likelihood ratio test results models under assumptions common different female male concluded has no difference genders.