Validation and otolith-mass prediction of age and growth for cardinal snapper Pristipomoides macrophthalmus of the Caribbean Sea

Abstract

Cardinal snapper Pristipomoides macrophthalmus is a commercially important, but commonly misidentified, deepwater species in artisanal and semi-industrial fisheries throughout the Caribbean Sea. As with many tropical deepwater fishes, little is known about the biology or ecology of the species. Bomb radiocarbon ( 14 C) dating was applied to cardinal snapper sagittal otoliths collected from the waters of Belize and Honduras during 2015–2019 to investigate the lifespan of the species from thin-sectioned otoliths with an evaluation of otolith mass as a proxy for age. Ages estimated from 28 thin-sectioned otoliths ranged from 7 to 68 years for fish that covered the range lengths and otolith masses available. Radiocarbon values were measured for each cardinal snapper otolith core, and two fish (one each from Belize and Honduras) had 14 C signatures consistent with pre-bomb values, effectively validating a lifespan of at least 60 years. A curvilinear relationship between otolith mass and estimated age was robust ( r 2 = 0.95) and is likely to produce age estimates with similar margins of error to traditional, more labor-intensive methods, such as counting increments from thin-sectioned otoliths. The otolith mass-to-age relationship is a well-supported method that provides a simple, low-cost approach that can be used by fishers, managers, and other stakeholders to assess the age composition of the cardinal snapper stock in the western Caribbean Sea for present and long-term monitoring.

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