A Review of Spawning Florida Largemouth Bass “Out of Season” Using Photoperiod and Temperature Manipulation to Produce Advanced Sized Fingerlings

Establishing a production – scale “Out of Season” (OS) spawning protocol to produce approximately 1,000,000 or more Florida Largemouth Bass Micropterus salmoides floridanus  swim-up fry in a three to four week period in the fall was the objective  of this research.  This manuscript reviews five years of spawning trials and results attempting to establish an OS spawning method.  The OS photo – thermal manipulation began each year approximately June 18^th and was completed by September 20^th.  The idea was to simulate winter to spring temperatures and day length over a 90 d period to naturally induce gonad development without the use of hormones.  Adult bass were stocked in the spawning raceways at a 1:1 and 2:3 male to female sex ratio (20 males to 20 or 30 females) and spawned in late September through mid October.  Total number of spawns collected (2009, 2010, and 2011) were 193, 205, and 199 represented an average 1.4, 2.0, and 1.0 spawns per female.  Spawning duration required to achieve production numbers were 26, 31, and 23 days.  The OS spawning technique allows for bi-annual production seasons from the same broodstock population and the production of large numbers of 100 mm bass by March.  Increased production, broodstock behavior, hatchery space efficiency, and temporal limitations are discussed.