Spotted seatrout mature at 1-4 years of age (Lorio and Perret 1980). Tabb (1961) reported that in the IRL, females mature at 3-4 years of age, while males mature at 2-3 years of age. Females tend to be larger at maturity than are males (Moody 1950; Moffett 1961). Length at maturity varies by region; however, most spotted seatrout spawn at 24-25 cm (9.4 - 9.8 inches) standard length (Moody 1950). Cynoscion nebulosus spawn in nearshore and estuarine waters (Mercer 1984; Johnson and Seaman 1986). They are multiple spawners, as evidenced by the presence of vitellogenic and fully yolked eggs in ovaries throughout the spawning season (Brown-Peterson et al. 1988). The average time between successive spawns was reported by Brown-Peterson et al. (1988) as 3.6 days, though data from an experimental aquaculture population yielded a period between spawns of 21 days (Tucker and Faulkner 1987). This indicates that a female may spawn 9 - 60 times in a spawning season, and release 3 - 20 million eggs annually (Murphy et al. 1999). Spawning occurs at somewhat different times depending on location. In Florida, spotted seatrout in the Ft. Myers area spawn from late March through September, with a peak in June (Moody 1950, Moffett 1961). In the Indian River Lagoon, spawning occurs from mid-April through July, peaking from April - June (Tabb 1961), though some data indicates year-round spawning within the IRL (Murphy and Taylor, FMRI, unpubl in Murphy et al. 1999). In the Everglades, evidence indicates year-round spawning that peaks both in spring and from late summer to early fall. (Jannke 1971; Rutherford et al. 1982). Time of spawning is controlled by temperature and salinity, with spotted seatrout in most areas spawning in waters where temperatures are 25 - 28ºC, and salinity is 30 - 35 ppt (Johnson and Seaman 1986).Fecundity increases with size in Cynoscion nebulosus. In Florida, Moody (1957) reported a 39.7 cm (15.6 inches) female collected at Cedar Key contained 464,000 eggs. Tabb (1961) reported 15,000 - 1.1 million eggs per female from a collection of females, aged at 4 - 8 years, and ranging in size from 32.5 - 62.5 cm (12.8 - 24.6 inches) standard length (SL). In a Louisiana study, Sundararaj and Suttkus (1962) reported that Age III females contribute approximately 41% of all eggs spawned, and thus have the greatest reproductive potential of all age classes. Age IV females contributed 27% of the eggs spawned, while Age II females contributed 24%. In an Everglades study, Rutherford et al. (1982) found that most male spawners were Ages II, III, and IV.