Reproductive seasonality, maturation, fecundity, and spawning frequency of the vermilion snapper, Rhomboplites aurorubens, off the southeastern United States

The vermilion snapper, Rhombplites aurorubens, is an important species in headboat and commercial reef fisheries in the southeastern United States, especially in the Carolinas. The reproductive biology of vermilion snapper was determined from samples collected on biweekly research cruises (April to August 1992 and May 1993) and from samples collected from commercial vessels (September to April 1992-93). Vermilion snapper did not exhibit a 1:1 sex ratio; 63% of the specimens were female. The reproductive season of vermilion snapper is April through late September in the southeastern United States. All vermilion snapper examined were mature, with the smallest female at 165 mm FL, the smallest male at 179 mm FL. The smallest fish aged (165 mm FL) was two years old. Length was the best predictor of batch fecundity (BF=0.0438FL super(2.508)). Vermilion snapper spawn approximately every five days or about 35 times a year. Atresia did not significantly affect fecundity estimates. Vermilion snapper is an indeterminate spawner; its oocytes mature continuously during the spawning season and there is no hiatus between the size distribution of the oocyte classes. Total fecundity did not decline ever the spawning season. Rather, it gradually increased through August and then declined in September. Mean oocyte diameter stayed constant over the reproductive season. The order of spawning batches was not consistent with the determinate fecundity prediction.