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Fishery Bulletin 100(4) 



a horseshoe-shaped corridor, running between the north- 

 western Pacific, across to the eastern Pacific and back to 

 the southwestern Pacific (Ward and Elscot, 2000). Accord- 

 ing to Reed's studies, the swordfish in our samples can be 

 considered a part of the northern population in the west- 

 ern Pacific Ocean. 



We found that anal-fin rays are useful for aging 

 swordfish; they are easily sampled without reducing the 

 economic value of the fish and can be read easily (the 

 growth rings stand out clearly). This aging tool is espe- 

 cially important because swordfish lack scales and their 

 yery small otoliths are not amenable to traditional aging 

 techniques (Ovchinnikov, 1971; Beckett, 1974;Tserpes and 

 Tsimenides, 1995). Moreover, fin rays can be easily stored 

 for future reexamination (Compean- Jimenez and Bard, 

 1983). One problem associated with the fin-ray method 

 used in our study, also indicated by Berkeley and Houde 

 (198.3) and Tserpes and Tsimenides (1995), was the pos- 

 sible existence of multiple bands and the missing first 

 annulus in larger fish. However, Gonzalez-Garces and 

 Fariiia-Perez (1983) and Tserpes and Tsimenides (1995) 

 noted that experienced readers could overcome the prob- 



