Reproductive biology of the gray triggerfish Balistes capriscus (Tetraodontiformes: Balistidae) in southeastern Brazil as a tool for fisheries management

Abstract The gray triggerfish, Balistes capriscus, is a reef-associated species that supports fisheries in eastern and western portions of the Atlantic. In Brazil, the species presents high commercial importance and has faced alarming biomass decreases over time. This study provides an update on gray triggerfish biological aspects and fisheries management measures in Brazil after 20 years of the first assessment. A total of 566 samples were obtained from artisanal fisheries from southeastern Brazil, ranging from the state of Espírito Santo to northern Rio de Janeiro, from February 2021 to February 2023. Fish ranged from 153.4 to 419.0 mm fork length (FL). The sample was composed mainly by mature individuals. Gonadosomatic index assessments suggest that the spawning season takes place mainly between December and February, peaking in December, coinciding with summer. The first maturation size is estimated at 230.9 mm FL (confidence intervals: 225–234 mm). Based on these data, we suggest altering the minimum capture size to 230 mm FL (currently 200 mm FL) as a recovery and management measure for gray triggerfish fisheries in southeastern Brazil and, if understood that current stocks require further recovery measures, the establishment of a closed gray triggerfish season between November and February.