Pernn et al.: Geographic variation in morphology of Stenella longirostns 



421 



Figure 14 



Percentages of adult male spinner dolphins having most 

 "eastern" (A), most pantropical/"whitebelly" (C), and in- 

 termediate combinations (B) of ventral field, cape, and dor- 

 sal fin, by area. 



Figure 15 



Percentages of adult female spinner dolphins having most 

 "eastern"-type (A), most pantropical/"whitebelly"-type (C), 

 and intermediate combinations (B) of ventral field, cape, and 

 dorsal fin, by area. 



two westernmost cells had falcate fins. This difference 

 is statistically significant (P< 0.0001: Fisher's exact 

 test, two-tailed). The frequency of falcate fins in the 

 two southwestern cells between 10°N and 5°S was in- 

 termediate (Fig. 12B). In females, the falcate fin was 

 also most common in the south, although in this case 

 the frequency there was not statistically different from 

 that in the two westernmost cells at P = 0.05. 



Combined characters 



Data on all three characters (ventral field, cape and 

 dorsal fin) were available for 610 sexually adult males 

 and 683 females. The distributions of the extreme ex- 

 pression of eastern character combinations (a total 

 score of 3 for males and 4 for females) and pantropical 

 combinations (10 for both males and females) were 

 similar for males and females (Figs. 14, 15). Only the 

 extreme eastern combination predominated (more than 

 50%) in any area, in a region bounded by 10°N and 



