Little is known about the life history of Labidesthes vanhyningi (Stout Silverside) in the Mobile Basin. We made monthly collections of Stout Silverside from Lake Tuscaloosa in Northport, AL, from September 2011 to September 2012. Emergence of young-of-the-year occurred in the months of September, October, January, and May. Reproductive investment, calculated using a gonadosomatic index (GSI), was observed from March to December. We also documented evidence for internal fertilization by Stout Silverside in the Mobile Basin. Dietary analysis showed cladocerans were the numerically dominant prey item. These life-history data provide information to natural resource-management agencies about Stout Silverside in the Mobile Basin, where the species is currently under threat from invading Menidia audens (Mississippi Silverside).