Development and assessment of an aging criteria for the main Hawaiian Islands crimson jobfish, Pristipomoides filamentosus (opakapaka)

The economic and cultural importance of the crimson jobfish Pristipomoides filamentosus has long placed it at the pinnacle of the Hawaiian deepwater handline fishery. Known locally as opakapaka, the species is assessed and managed as part of a seven species bottomfish complex called the “Deep-7.” To provide length at age and somatic growth information for an age-based single-species stock assessment, we examined opakapaka otolith microstructure and age interpretation. Using standardized thin-sectioning methods for age estimation, we developed an ageing criterion based on (1) daily increment counts to confirm the location of first annulus, (2) evaluation of otolith shape between younger and older fish, and (3) comparison of annulus counts with the bomb radiocarbon age of each specimens. Between-reader age-precision estimates were at acceptable levels for deep-water species (5.5% APE, 7.7% CV). We conclude that the application of this ageing criterion to thin otolith sections is a suitable method for the determination of annual age estimates for opakapaka between 1 and 44 years old. The resulting criterion will be a reference for estimating future age compositions of the fishery and evaluation of main Hawaiian Islands sex-specific growth of P. filamentosus. 2020 NMFS (National Marine Fisheries Service) PIFSC (Pacific Islands Fisheries Science Center) Submitted https://doi.org/10.25923/1dcr-gz45 Public Domain 1861