FISHERY BULLETIN: VOL. 87, NO. 4, 1989 



Figure 6. — Left sagitta from a 80. 1 kg male Pacific Makaira nigrkans. 

 for age estimation. R = rosti-um; A = antirostrum; C = core region; 

 ridges. 



Arrows indicate rostral ridges quantified 

 calcium carbonate overburden obscuring 



0.01) between corresponding annuli for these 

 two sets of data for either anal or dorsal spines; 

 therefore, these two data sets were combined. 

 There was, however, a significant difference in 

 corresponding anal and dorsal spine band radii 

 between males and females from the sixth band 

 outward; therefore data were separated by sex 

 (Fig. 8A, B). 



Increment counts (sagitta ridges, corrected 

 spine bands, and vertebral increments) in- 

 creased with hardpart growth for each of the 

 four structures considered. This relationship 

 was logarithmic when increment counts were 

 compared to AR, DR, and SW, and linear when 

 compared to CD for both sexes (Table 3). Coeffi- 

 cients of determination were higher for females 

 in all cases, and ranged from r = 0.39 for male 

 dorsal spines to r^ = 0.83 for female dorsal 

 spines. 



Hardpart Comparisons 



There was a positive linear relationship be- 

 tween estimated counts of corrected growth in- 



Table 3 — Modeled relationships between hardpart growth and 

 increment counts for Pacific Makaira nigricans. LJFL = 

 lower jaw-fork length, W = roundweight, AR = anal spine 

 radius, DR = dorsal spine radius, SW = sagitta weight, CD = 

 centrum cone depth, AC = corrected anal spine band counts, 

 DC = corrected dorsal spine band counts, SC = sagittal ridge 

 counts, VC = vertebral increment counts. 



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