FISHERY BULLETIN: VOL 85. NO. 4 



were brought to natural size by reference to the 

 centimeter scale in each photograph. Accuracy 

 was ensured for body-depth measurements by 

 using a right-angle scale on the body axis. 



The study used 18 linear measurements'^ 

 (nearest millimeter) in addition to standard 

 length (SL) of approximately 1,500 specimens 

 sampled from the Bering Sea and Gulf of Alaska 

 during summers of 1968-70 (Fig. 1, Table 1). The 

 measurements gave major dimensions of the body 

 and accessory structures, similar to those stand- 

 ard in taxonomic studies (Hubbs and Lagler 

 1949): 



Standard length . — From tip of the premaxillary 

 to the skin deflection (evidenced by a change in 

 shading) at end of the hypural plate. 



Nape. — From tip of premaxillary to the anterior 

 insertion (junction of anterior outline with body 

 profile) of the first spinous ray in the dorsal fin. 



Spinous dorsal-fin length. — From anterior inser- 

 tion of the spinous dorsal fin to the posterior 



3Data for the measurements, including additional measure- 

 ments not given in this paper, are available on tape as JQUAST/ 

 MORFl on file at the Northwest and Alaska Fisheries Center, 

 National Marine Fisheries Service, 2725 Montlake Blvd. East, 

 Seattle, WA 98112 



insertion (junction of posterior outline of spine 

 with body profile) of the 13th spinous fin ray. 



Hind-trunk dorsal. — From posterior insertion of 

 the 13th spinous fin ray to end of the hypural 

 plate. 



Hind-trunk ventral. — From posterior insertion of 

 the second anal-fin spine to end of the hypural 

 plate. 



Belly. —From posterior insertion of the pelvic fin 

 to posterior insertion of second anal-fin spine. 



Pelvic insertion. — From tip of the premaxillary to 

 posterior insertion of the pelvic fin. 



Head. — From tip of the premaxillary to posterior 

 edge of the opercular fiap. 



Body-depth pelvic. — Dorsoventral distance, tak- 

 en perpendicular to the longitudinal axis of the 

 fish, from the posterior insertion of pelvic fin to 

 dorsal body outline. 



Body-depth anal. — Dorsoventral distance, taken 

 perpendicular to the longitudinal axis of the 

 fish, from the anterior insertion of first anal 

 spine to dorsal body outline. 



Caudal peduncle. — Shortest distance across cau- 

 dal peduncle, taken perpendicular to its longi- 

 tudinal axis. 



Orbit.— Greatest diameter between opposite sides 

 of the orbit, taken parallel to longitudinal axis 



k^ 



60- 



55- 



50- 



ATKA-GULF 



GULF OF ALASKA 



VANCOUVER 



-J L 



 I I I I I I 



I I I I I I I I I I I I 



I I I I 



I I I I 



'III 



1_L 



I I I 



170 165 160 155 150 145 140 135 130 



Figure 1. — Geographic regions and statistical areas (dark rectangles) where Pacific ocean perch were obtained 



for this study. 



664 



