550 



Fishery Bulletin 102(3) 



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Hatching date 



Figure 4 



Hatch-date distributions of S. dumerili associated with Sargassum mats 

 in 2000 and 2001. 



attributed the distribution of fishes from nearshore to 

 offshore stations to environmental factors, season, and 

 life history strategies. Furthermore, the combination of 



available resources (i.e. food and habitat), seasons, and 

 physiochemical tolerances may account for the observed 

 spatial patterns of habitat use. 



Temporal patterns of size-specific habitat use showed 

 similar trends between years and appeared to be relat- 

 ed to spawning season. Relative abundance of small S. 

 dumerili was highest early in the season (May), declined 

 in June, and further increased late into the season 

 (July) for both 2000 and 2001. Nevertheless, small juve- 

 niles were collected during the entire collection period, 

 which suggests that S. dumerili spawning in the NW 

 Gulf is protracted. Previous studies have found that 

 S. dumerili spawn throughout the spring and summer 

 months ( March- July) (Marino et al., 1995; Cummings 

 and McClellan, 1996). In addition, Fahay (1975) sug- 

 gested, on the basis of larval collections in the western 

 Atlantic, that spawning occurs in the winter. Despite 

 the limited duration of our collection efforts, our results 

 are consistent with these findings with 63% of year- 

 2000 S. dumerili and 36 f > of year-2001 fish resulting 

 from spring spawning events. The remaining individu- 

 als were spawned January through early March. 



Growth estimates indicated that S. dumerili have 

 rapid growth throughout early life stages. Based on 

 linear growth models, average growth of S. dumerili 

 was 1.45 mm/d — an estimate similar to that of Manooch 

 and Potts's (1997b) study in the Gulf (average growth of 

 1.17 mm/d for age-1 individuals). However, growth com- 

 parisons may be invalid because their study estimated 

 growth based on counts of annuli and no temperature 



