764 



Fishery Bulletin 90(4), 1992 



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FATNESS INDEX 



Figure 4 



Frequency histograms of fatness index are shown for Japanese commercial catch of pelagic armorhead Pseudopentaceros wheeleri in 

 (A) each year during 1978-84 and (B) for each of the research cruises during 1985-90. 



of the extant armorhead population in January 1985, was 

 identifiable for seven consecutive samplings and had an 

 instantaneous natural mortality (M) of 0.054/mo. The 

 second, which consisted of the year-class recruiting in 

 1986, was identifiable for eight consecutive samplings and 

 had an M of 0.044/mo (Fig. 6). Although the two estimates 

 were significantly different (ANCOVA, P<0.05), the 

 weighted average (0.045/mo or 0.54/yr) was chosen as 



Figure 5 



Decrease in fatness index of pelagic armorhead Pseudopen- 

 tnceroa wheeleri with time for the 1980 and 1986 year-classes 

 on Southeast Hancock Seamount. 



