Age, Growth, and Reproduction of Vermilion Snapper in the North‐Central Gulf of Mexico

Abstract

AbstractVermilion Snapper Rhomboplites aurorubens is a commonly harvested species of reef fish in the northern Gulf of Mexico (GOM) and supports large commercial and recreational fisheries. Vermilion Snapper (139–535 mm TL) were collected from May 2015 through October 2016 from artificial and natural reefs in the north‐central GOM. Ages ranged from 0.8 to 13 years, and there was no significant difference in growth between males and females. Nonlinear curve fitting was used to estimate growth parameters and Akaike information criterion (AIC) was used to determine relative model fit. The two‐parameter von Bertalanffy growth function provided the best model fit and lowest ΔAIC score. Histological examination indicated that Vermilion Snapper are batch spawners with asynchronous oocyte development. Additionally, 17% of female Vermilion Snapper in the actively spawning subphase had 24‐h postovulatory follicles (POF) suggesting daily spawning is occurring. No immature fish of either sex were collected during this study. Both histologically determined phases and gonadosomatic index patterns defined a spawning season occurring from April through September. The spawning interval for Vermilion Snapper, 1.3 and 2.1 d, was estimated using the hydrated oocyte and POF methods, respectively. Batch fecundity estimates from 5,497 to 284,468 eggs per batch were determined using fish macroscopically classified as actively spawning (n = 25), and total annual fecundity was estimated to range from 450,754 to 32,549,776 eggs per spawning season. Mean relative batch fecundity was 70.7 eggs/g of gonad‐free body weight. Estimates from this study can be directly incorporated into population assessments and provide a region‐specific overview of the life history for the Vermilion Snapper from the north‐central GOM.