FISHERY BULLETIN: VOL. 85, NO. 4 



scribed in Westrheim and Shaw (1982). Otoliths 

 must be sectioned with a low-speed electric saw 

 and burnt with care, as they are quite brittle. The 

 interpretation of annuli on break-and-burn sur- 

 faces was adapted from that of walleye pollock 

 (Lai and Yeh 1986). 



The coracoid is a dermal bone connected to the 

 scapula and radii in the pectoral girdle. A trian- 



gular component within the coracoid (Fig. 1) 

 shows alternate opaque (dark) and translucent 

 (light) zones under a binocular microscope and 

 transmitted light, by which annuli can be identi- 

 fied. The center of this structure occasionally con- 

 tains some checks that are parallel to the an- 

 nulus; however, their spacing is narrower than 

 that of regular annuli. The age samples were read 



Figure 1. — Upper: The pectoral girdle. A, coracoid; B, scalpula; C, radii; D, the portion used for 

 age determination. Lower: Enlarged Part D. •, translucent zone, counted as an annulus. 



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