Reproductive Biology and Lipid Characteristics of Gulf Menhaden, Brevoortia patronus

Gulf Menhaden, Brevoortia patronus, are considered an important “forage” fish stock and supports a commercial fishery in the northern Gulf of Mexico (GOM). Although the peak reproductive season of the stock is reported to be from November to February, our analysis of Gulf Menhaden collected during August through October 2014 indicates that >65% of both sexes are spawning capable by early October, and that 20% of females are actively spawning in late October. Histological analysis indicates that Gulf Menhaden exhibit a determinate fecundity pattern but are batch spawners, with preliminary fecundity estimates of 59,423 eggs/batch. Mean standard length (SL, mm) at 50% maturity for females (133.5) and males (138.5) indicates that the fishery targets sexually mature individuals in the fall. There is a positive, weak correlation in lipid concentration of muscle tissue and condition of sexually mature fish (Fulton’s condition factor, R=0.18). There are no significant differences in mean muscle lipid density between males and females, but immature fish have significantly lower (p<0.001) lipid density than sexually mature females. Fatty acid analyses will provide additional information. These data suggest Gulf Menhaden make a significant reproductive and fatty acid contribution to the GOM ecosystem during the fall commercial fishery season.