586 



Fishery Bulletin 100(3) 



Figure 2 



A whole (A) and sectioned (B) sagitta from a 7-year-old l230-mm-SL) pinfish 

 caught in Tampa Bay in November 1993. 



is formed only once a year, during late winter to late spring. 

 Deposition of opaque material began as early as January; 

 it peaked during March, April, or May depending on age; 

 and it was completed, or nearly so. by June (Fig. 3). 



A single regression equation characterized the relation- 

 ship between otolith length (OT in mm) and standard 

 length for a random sample of pinfish 71-230 mm SL 

 (standard errors are in parentheses) used in age analysis: 



or =8.03(1.07) -I- 0.39(0.008) xSL; \r- = 0.95,n = 132]. 



The intercept and slope coefficients were significantly dif- 

 ferent from zero (P<0.001). 



Ages of pinfish ranged from to 7 years (66-255 mm 

 SL) in Tampa Bay and from 1 to 6 years (95-175 mm SL) 

 in the Gulf of Mexico (Fig. 4A). The majority (88.1%) of 



aged pinfish were <2 years. Residual plots from the growth 

 models showed near-random patterns, indicating that the 

 von Bertalanffy model adequately described the growth 

 of male and female pinfish. Results of the randomization 

 test did not indicate a significant difference between male 

 and female growth models (^(.to)=2,691;p(«:»:)>«j:o))=0.27); 

 therefore, a von Bertalanffy model was fitted to all pinfish 

 data combined I Fig. 4B, Table 3). Growth rate of pinfish 

 was rapid for the first 1-3 years of life but gradually de- 

 creased thereafter (Fig. 4B). 



Reproduction, maturity, and sex ratios 



Seasonality of reproduction was indicated by monthly 

 changes in the GSIs of all pinfish over time. In Tampa Bay 

 and the Gulf of Mexico, GSIs for males and females were 

 <0.5'7f' during the spring and summer months (Fig. 5). 



