FISHERY BULLETIN: VOL. 85, NO. 4 



and erase local differentiation. Further, the spe- 

 cies appears to be genetically nearly homoge- 

 neous over as great, and environmentally vari- 

 able, a distance in the eastern part of its 

 range — Seeb and Gunderson (in press) demon- 

 strated "very high similarity" among populations 

 from Washington State to the Bering Sea and 

 found no evidence for a barrier at the Aleutian 

 Chain. Second, as already mentioned, morpholog- 

 ical (including morphometric) differences can be 

 environmentally induced through modification of 

 growth rate. The growth differences Quast (fn. 2) 

 found, which appeared to conform more closely to 

 latitude than ocean temperatures, resemble geo- 

 graphic trends in some measurements examined 

 in the present study, including body-depth pelvic 

 (Fig. 2H). Last, Barsukov's criteria for the sub- 

 species can be called into question. When referred 

 to fish of two standard sizes, 260 and 300 mm SL, 

 my data on body-depth pelvic (Barsukov's "body 

 depth") indicate that only representatives from 

 the Kodiak region have 95% confidence limits for 

 mean population values that lie consistently on 

 the S. a. alutus (the nominal eastern subspecies) 



side of Barsukov's criterion-confidence limits 

 for most measurement means for other regions 

 indicate ambiguous or improper identification 

 (Table 5), and that a majority of specimens will 

 be improperly identified. Further, neighboring 

 populations in the eastern subspecies' range 

 frequently differ significantly in one or more 

 measurements (Fig. 2, Table 2). If significant 

 geographic variation were a sole criterion for 

 subspecies then a number might need be 

 named. 



Barsukov (1964) gave further criteria for sepa- 

 rating the nominal eastern and western subspe- 

 cies, but the criteria seem subjective and imprac- 

 tical: Prominence and apparent squamation of 

 occipital crests do not seem of value; as I have 

 observed, development of crests may be highly 

 variable within regions, and evidence for squa- 

 mation can be altered in specimens collected by 

 bottom trawl. His analysis of variation in the oc- 

 cipital crests is too short and subjective to be use- 

 ful. Size of symphyseal knob ("larger at similar 

 body lengths in the eastern subspecies") is not 

 reliable because the character has considerable 



Table 5. — Mean, upper, and lower 95% confidence limits for the mean of body-deptfi pelvic (BDP) measurements and 

 their derived proportions of standard length (SL) for Pacific ocean perch of 260 and 300 mm SL. Ratios of SL divided 

 by body depth are categorized according to Barsukov's (1964) criterion of 3.2 for the ratio as follows: Ratios rounding 

 to greater than the interval 3.15-3.24 (3.2 expanded to its inclusive values with two decimal points) are followed by a 

 blank, those within the interval are followed by an "A", and those lower are followed by an 1". Ratios followed by a blank 

 would identify the eastern nominal subspecies (S. a. alutus) by the 3.2 criterion, those followed by an "A" would give 

 an ambiguous identification (S. a. alutus or S. a. paucispinosus), and those followed by an '!" would identify the 

 western nominal subspecies (S. a. paucispinosus). 



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