FISHERY BULLETIN: VOL. 85, NO. 2 



mation. In August, only fish with previtellogenic 

 ovaries (stage I) were collected. During September 

 and October, a variety of ovary stages were ob- 

 served, from previtellogenic (stage I) to prespawn- 

 ing (stage IV). Ovaries with active recruitment of 

 oocytes into vitellogenesis (stages Ila and b) were 

 not observed after October. The first postspawn fish 

 (stage VI) was caught in late November, and by 

 January only previtellogenic or postspawn fish were 

 caught. Variation in ovary stages during the 1984-85 

 season (not shown) was similar, except that in this 

 year females with prespawning (stage IV) ovaries 

 were collected as late as mid-January. 



Fecundity 



Because oocyte size-frequency profiles indicate 

 that only a single clutch of developing oocytes pro- 

 ceeds through vitellogenesis in a season, and that 

 this single clutch is eventually spawned in its entire- 

 ty, it is possible to calculate the individual fecundity 

 of a female striped mullet by counting the number 

 of vitellogenic oocytes in stages Illa-IV ovaries (in 

 which recruitment of oocytes into developing 

 clutches has ceased). The annual potential fecundity, 

 or number of eggs available to be spawned in a 

 single breeding season, was thus found to be linearly 

 related to body weight and geometrically related to 

 standard length (Fig. 8). The lowest fecundity 

 observed was 0.25 x 10^ eggs in a fish 264 g BW 

 and 23.5 cm SL, and the highest fecundity was 2.2 

 X 10^ eggs in a fish 1,627 g BW and 44 cm SL. 



DISCUSSION 



The present results indirectly confirm that the 

 spawning season of M. cephalus in coastal waters 

 of northeast Florida extends from at least late 

 November (when the first postspawn female was 

 collected during the 1985-86 season) through mid- 

 January (when the last prespawn female was col- 

 lected during the 1984-85 season). However, there 

 is probably a certain amount of year-to-year vari- 

 ation within this range: the first postspawn female 

 was not observed until December during one season 

 (1984-85), while the last prespawn in another 

 (1985-86) was collected in December rather than 

 January. 



It is also probable that these dates are in reality 

 only a conservative estimate of the actual range of 

 the striped mullet spawning season in this area. 

 Available evidence from other studies strongly sug- 

 gest that striped mullet spawn offshore (Anderson 

 1958; Arnold and Thompson 1958; Finucane et al. 



1978). If this is also true of striped mullet in north- 

 east Florida, then postspawn females collected in 

 November may have traveled extensively between 

 spawning at offshore sites and their eventual cap- 

 ture in the Inlet. Likewise, the prespawn females 

 collected in January would have required some time 

 to reach offshore spawning sites after leaving the 

 Inlet. Therefore, adding a month to each end of the 

 observed range to conservatively account for such 

 migrations may be appropriate and would make our 

 dates consistent with previously published reports 

 of spawning times for striped mullet in the south- 

 east United States ranging from October through 

 February (Broadhead 1956; Anderson 1958; Dindo 

 and MacGregor 1981). 



Do striped mullet of northeast Florida actually 

 spawn offshore? The best evidence for offshore 

 spawning migrations in this study was our failure 

 to collect from the Inlet any females with spawn- 

 ing ovaries or even partially spent ovaries, suggest- 

 ing that spawning probably occurred some distance 

 from the Inlet. Further evidence for an offshore 

 spawning site were the abrupt disappearances from 

 the Inlet of fish with prespawning ovaries during 

 both years of the study (mid- January 1984-85 and 

 mid-December 1985-86), as this behavior suggested 

 that mass spawning migrations to offshore waters 

 occurred at these times. 



If these disappearances did represent mass off- 

 shore spawning migrations, then how can we explain 

 the earlier appearances in the Inlet of a few post- 

 spawn fish? Perhaps there are actually multiple 

 spawning migrations, possibly by different popula- 

 tions of striped mullet moving through the Inlet at 

 intervals throughout the period. Or perhaps some 

 inshore spawning also occurs: staff at the Whitney 

 Laboratory* have occasionally observed what they 

 considered to be striped mullet spawning activity 

 in the Intracoastal Waterway near the Inlet, and 

 there are a few anecdotal accounts of inshore spawn- 

 ing in the hterature (Breder 1940; Gunter 1945; 

 Timoshek and Shilenkova 1975). However, if inshore 

 spawning does occur, it must be limited in scope; 

 otherwise, we would have collected females with 

 spawning ovaries in the Inlet during our own 

 studies. It may be that striped mullet can spawn 

 either inshore or offshore, with offshore spawning 

 favored, depending on factors— such as salinity, 

 temperature, winds, currents, tides, or some com- 

 bination thereof— which vary from locale to locale 

 and from year to year. 



^W. Raulerson, Whitney Laboratory, University of Florida, 

 Route 1, Box 121, St. Augustine, FL 32086, pers. commun. 



196 



