Factors Influencing Individual Reproductive Success of Largemouth Bass Spawned in an Indoor Hatchery Raceway

Largemouth bass (Micropterus salmoides) are one of the most highly targeted freshwater species in North America.  Hatchery production of largemouth bass in Florida now plays an integral role in their management, with the primary goal focused on supplementing natural populations as a means to compensate for potential losses in recruitment due to habitat degradation and fishing mortality.  Raceway spawning has become the method of choice (over pond breeding) because it permits for greater control and efficiency over the reproductive process.  One assumption in raceway spawning is that reproductive contribution of individuals will remain similar to that in natural populations where spawning is monogamous, and individual reproductive contributions will be high.   We collected genetic material from brood-stock and eggs from three indoor spawning raceways stocked with 21 or 18 pairs of bass, spawned over a 4 week period in 2008.  We generated microsatellite genotypes for approximately 10 eggs per spawn (70 total spawning events) to quantify individual contributions and mating patterns.   Progeny were assigned to potential broods using both full-probability and likelihood based parentage assignments.  We examined factors including size, weight, genetic relatedness, and date of spawning event to explain individual spawning success.