Reproductive biology of female southern kingfish within the Mississippi Sound

Southern kingfish, Menticirrhus americanus, is an important commercial and recreational fishery along the Mississippi Gulf Coast; however annual harvest has declined over the last decade. Little is known regarding the reproductive biology of this currently unregulated species. Therefore, the purpose of this study is to estimate the spawning season, spawning frequency, fecundity, and age and size at maturity of female southern kingfish in Mississippi. Specimens (n=434) were collected using hook and line within the Mississippi Sound from April 2008 through May 2009. The smallest sexually mature fish was 140 mm SL, likely corresponding to age 1. Gonadosomatic Index values were elevated from March to September, with a peak in April. Histological analysis showed ovarian development began in February and March, and spawning capable fish were found from late March through early October. Actively spawning fish undergoing oocyte maturation were found from April to September. Southern kingfish are batch spawners and appear to have a six month spawning period in Mississippi. Average spawning frequency was estimated to be every 6.93 days. The reproductive data generated from this project could aide fisheries managers in protecting the spawning stock of the southern kingfish.