FISHERY BULLETIN: VOL. 85, NO. 4 



ATKA-B, ATKA-G, KOD , YAK , SE 



REGION 

 VAN ATKA-B, ATKA-G, KOD , YAK , SE , VAN 



Figure 2.— Continued. 



ated pelvic fins and the complex of anal-fin spines 

 moved relationally apart (Fig. 2F, D). In contrast, 

 depth of the entire body of Pacific ocean perch 

 varied similarly geographically because the three 

 measures of body depth — body-depth pelvic, 

 body-depth anal, and caudal peduncle — varied 

 concordantly (Fig. 3). 



Sexual dimorphism was significant in most 

 measurements, and except for belly size, mea- 

 surements usually averaged larger in males than 

 in females. The combined effects of geographic 

 and sexual variation meant that belly measure- 

 ments averaged about 16 mm larger in standard- 

 sized females from the Atka-Bering region than 

 in males from the Southeastern or Vancouver re- 

 gion (Fig. 2E). 



Slopes in over one-half of the measurement re- 

 gressions differed significantly from unity (Table 

 2), indicating growth allometry, particularly 

 when differences from unity were consistent. The 

 symphyseal knob was the only character with 

 strong positive allometry (Table 2). Only two 

 characters were strongly or consistently nega- 

 tively allometric (Table 2): hind-trunk ventral, 

 significant in 11 of 12 sex/region cells (slopes av- 

 eraging 0.94 in males and 0.87 in females); and 

 length of 3d anal-fin spine, significant in all 12 

 sex/region cells (slopes averaging 0.72 in males 

 and 0.74 in females). With growth, the trunk pos- 

 terior to the anal-fin spines becomes proportion- 

 ally smaller relative to the rest of the body be- 

 cause of negative allometry in the body-depth 



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BODY-DEPTH PELVIC 



BODY-DEPTH ANAL 



CAUDAL PEDUNCLE 



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Figure 3. — Geographic variation in depth measurements of 

 three body characters in Pacific ocean perch. Character mea- 

 surements were related to a standard-sized fish of 260 mm SL 

 from regressions in Table 2, then back transformed. Because 

 measurements for males and females were usually different 

 (Fig. 2), midvalues between sexes were used. Percentage change 

 is the change in a measurement between neighboring regions as 

 a percentage of the measurement's range over the geographic 

 range. 



anal, hind-trunk ventral, and caudal peduncle 

 measurements. 



674 



