310 



Fishery Bulletin 103(2) 



J 



I 



 Males 

 □ Females 



ill 



225 275 325 375 425 475 525 575 625 675 725 

 Total length (mm) 



6 -i 



5 



4 



200 800 1400 2000 2600 3200 3800 4400 5000 5600 

 Total weight (g) 



Figure 1 



Distributions of (A) total length in mm (n = 837) and (B) total weight 

 in g (/i = 832) for gray snapper (Lutjanus griseus) sampled from the 

 Louisiana 1998-2002 recreational harvest. 



TL for females. A Komolgorov-Smirnov two-sample test 

 indicated no significant difference between male and 

 female TL frequencies (maximum difference=9.45). Male 

 and female TW ranged from 200 to 5700 g and 300 

 to 5800 g TW, respectively (Fig. IB). Both sexes also 

 displayed multimodal distributions in TW. A Komol- 

 gorov-Smirnov two-sample test indicated a significant 

 difference between sexes at 1600 g TW (maximum dif- 

 ference=9.67). A single predictive TL-TW regression was 

 generated for both males and females: 



TW = 3. .31 x 10- 5 (TL 285 ) 



(Fj 822 =9,326.54; P<0.001; r 2 =0.92). 



Significant differences were found between sexes in 

 TL-TW relationships (ANCOVA test of homogeneity of 

 slopes, F 3 822 =7.25; P=0.007; r 2 =0.92). Therefore, sepa- 

 rate models were fitted for each sex: 



Males 



2.04 x 10 -B(x 2 - 93 ) 



7588.29; P<0.001; r 2 



TW 



( ^l,436 



Females = TW = 5.5 x 10- 5 (7/L 277 > 



= 0.95) 



Gray snapper otoliths are very similar in physical struc- 

 ture, although much smaller in actual size, to those of 

 the red snapper. Opaque zones are easily distinguishable 

 on the ventral side of the sulcus groove (Manooch and 

 Matheson, 1981; Johnson et al., 1994; Shipp 2 ) (Fig. 2, 

 A and B). 



Sagittae were collected from 721 gray snapper of 

 which 718 were aged. Readers were unable to resolve 

 opaque zones in three otolith sections because of poor 

 sectioning. Readers agreed on the ages of 568 indi- 

 viduals (78.8%) after initial counts and differed by one 

 opaque annulus for 154 specimens, two annuli for 18 

 specimens, and three annuli for 2 specimens. Readers 

 agreed on 709 ages (98.7%) after the second reading. 

 The average percent error (APE) was 0.5, coefficient of 

 variation (CV) was 0.00078, and index of percent (D) 

 was 0.0006. 



cf, 



385 



= 3,089.16; P<0.001; r 2 =0.89> 



2 Shipp, R. L. 1991. Investigations of life history parameters 

 of species of secondarily targeted reef fish and dolphin in 

 the northern Gulf of Mexico. Proc. Fourth Annu. MARFIN 

 Conf., San Antonio, TX, p 80-85. [Available from National 

 Marine Fisheries Service, State/Federal Liaison Office, 9721 

 Executive Center DR. N., St. Petersburg, FL 33702.1 



