Growth, Spawning, and Management Patterns of Female Euthynnus affinis (Cantor, 1849)) Landed in Kedonganan, Bali

Abstract Euthynnus affinis (Cantor, 1849)) is a type of tuna that lives in a tropical environment, with a neritic climate spread across the Indian and Pacific Oceans, and has exceeded the catch limit. So, the spawning time must be known to show a quantitative index that shows the condition of fish gonad maturity, often called the gonad maturity index. The spawning season or time occurs when gonad maturity index values in both sexes reach the highest level. A total of 235 fish samples were used, with 73 samples of male gonads and 109 samples of female gonads, and 53 samples were not identified by sex. The biological sampling protocol used a sub-sampling system with a purposive stratified sampling method. Data was collected by direct observation at the Kedonganan Fish Landing Base in 2020. The results showed that the female komo tuna’s growth pattern has a positive allometric pattern with a 26.5-58 cm FL length distribution. The sex ratio is balanced at gonad maturity. The spawning of komo tuna has an asynchronous type and partial spawner nature, spawning at night and spawning throughout the year with peak spawning seasons in August and December.