Advancing technologies and specialised gear are driving the expansion of eastern Australia's recreational deep-water line fishery where flame snapper (Etelis coruscans) are targeted for their high eating quality. There is a lack of baseline biological data in eastern Australia to manage the impacts of increasing fishing pressure on this widespread species. To address this, we combined population genomics and life-history analyses for line-caught E. coruscans collected from August 2023 to April 2026 from Queensland waters over a large latitudinal gradient (-15°S to -27°S).
Population connectivity Single Nucleotide Polymorphism (SNP) analyses revealed a single panmictic stock off Queensland with high gene flow, low genetic diversity and low regional differentiation. Fish ranged from 32 to 90 cm fork length, with females reaching a greater length than males. Age ranged from 4 to 39 years, with fastest growth up to age 11 and males growing marginally faster than females. Validated macroscopic gonad staging and the gonadosomatic index (GSI) revealed peak female GSI occurred during Austral summer, with spawning fish restricted to tropical northern Queensland (-17°S). Female length at 50% maturity (L50) far exceeds the current legal size limit for Queensland. These results demonstrate E. coruscans in eastern Australia are long-lived, slow growing, and late to mature; traits which make them prone to overexploitation.
These findings provide the first insights into the biology and population structure of Australian E. coruscans and expand the knowledge of this species across its wide geographic distribution. Given the shifting dynamics of this specialised deep-water fishery, this study highlights the need for quantifying recreational catch rates and further investigation into the reproductive behaviour of this species to inform management decisions.