KATZ ET AL.: DELINEATION OF TILEFISH STOCKS 



E 

 E 



en 



c 



a. 



CO 



<o 

 o 



D. 



< 



400 



500 600 700 



Standard Length (mm) 



800 



900 



FIGURE 4.— Adipose flap length plotted against standard length for male tilefish from the U.S. east coast and the Gulf of Mexico. 



Table 5. — Comparison of size adjusted morphological characters (least squares means in mm) 

 for male and female tilefish by covariance analysis. Independent variable is standard length. 

 ** = p<0.01. 



observed (Fig. 3), we reject the null hypothesis 

 and suggest that there are at least two distinct 

 groups in the samples examined, a Mid-Atlantic 

 Bight group and a second group composed of 

 samples from South Carolina and the Gulf of 

 Mexico. This is supported by concordance in the 

 patterns of variation for both EST and IDH (Fig. 

 3). 



The morphological data consistently support 

 the concept of a single group of fish in the Mid- 

 Atlantic Bight but varies for other areas. Both 

 meristic and morphometric data for both sexes 

 in the Mid-Atlantic Bight show little significant 



variation (Tables 3, 4, 6, 7), suggesting that these 

 are freely interbreeding populations. The Gulf of 

 Mexico samples appear completely distinct from 

 Mid-Atlantic Bight samples by the same analy- 

 sis. The morphological analyses of the South 

 Carolina samples were contradictory with the 

 electrophoretic results. The comparisons of least 

 squares mean values for morphometric charac- 

 ters for the South Carolina samples to the Mid- 

 Atlantic Bight samples (Tables 3, 4) consistently 

 indicated no significant differences. However, 

 the South Carolina samples differed significantly 

 in total gill raker number as did the Gulf of 



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