Length-based Population Parameters of Shortfin Scad (Decapterus macrosoma) in Bali Strait Waters, Indonesia

Abstract

Shortfin scad (Decapterus macrosoma) is one of the most abundant catch of the purse seiners in Bali strait. The aims of this study were to reveal the length-length relationship, the length-weight relationship, and to estimate the first size of maturity and the first size of captured for shortfin scad in Bali Straits waters. The samples were collected from Pengambengan Fishing Port from June to December 2018. A total of 3,341 shortfin scads were fork length measured and weighed during the study. There were 420 fish from the total sample fish that were measured more for the total length and standard length and dissected. The sex and maturation stage determination were identified by gonad visual characteristics. The relationship between length was determined using linear regression, whereas the length-weight relationship was done by using power regression. The first size of maturity and capture were determined using the logistic curve. All length measurement methods were highly related to each other and to the weight. The growth pattern of shortfin scad were hyperallometric. The first size of maturity for D. macrosoma was 164 mmTL for male and 162 mmTL for females. They were shorter than the length at first capture, which was 184 mmTL.