Demographic differences in reproductive biology of female red snapper (Lutjanus campechanus) in the northern Gulf of Mexico

This study provides critical information about Gulf of Mexico red snapper life history and reproduction and provides insight to their population structure. Over 3,500 fish were collected in the northern Gulf of Mexico west and east of the Mississippi River (hereafter River) (Louisiana to Alabama) during three spawning seasons (1999–2001). Diel spawning periodicity, age- and size-at-maturity, batch fecundity, and spawning frequency estimates were determined. Red snapper diel spawning occurred during the mid- to late afternoon. Batch fecundity and spawning frequency generally increased with fork length, ovary free body weight, and age. Age- and size-at-maturity, and batch fecundity and spawning frequency estimates differed west and east of the River. Younger females collected east of the River were greater contributors to the spawning population, whereas west of the River older females were more important. Differences in reproductive biology between the two broad geographic regions may be due to juvenescence as a result of different fishing pressures and could influence management policies.