Abstract

Gray triggerfish Balistes capriscus is the most exploited balistid species along the coasts of the Southeastern U.S. Because gray triggerfish are exploited by recreational and commercial fisheries, stock assessments are essential in managing the resource. The most reliable stock assessments utilize fish age data to estimate age structure of the population, growth rates, and mortality. Reviews of fish ageing studies suggest that sagittal otoliths are the preferred ageing structures versus other bony structures (Campana 2001). Gray triggerfish otoliths are small, fragile, and difficult to extract and age. For these reasons, the first dorsal spine is used as the primary ageing structure for gray triggerfish stock assessments. Various ageing studies have noted difficulty in identifying the growth zones on gray triggerfish dorsal spines (Bernardes, 2002; Burton et al. 2015). The current study sought to validate the annual deposition of growth zones on dorsal spines, vertebrae, and otoliths of gray triggerfish through chemical marking (Potts et al, in prep).

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