FISHERY BULLETIN: VOL. 74, NO. 3 



shape of the frequency distribution differed sub- 

 stanially between sexes (Figure 4). The 240.5-cm 

 male age-group separated in the first quarter that 

 had zero variance (Table 5) was regarded as false 

 and was not used in subsequent calculations. 

 Quantitatively, the chi-square values do not in- 

 dicate very good fit; however, as was the case with 

 striped marlin, the tails of the frequency distribu- 

 tions, having frequencies too small for the separ- 

 ation of age-groups, contributed disproportiona- 

 tely to the total chi-square value. Qualitatively, as 

 can be seen from Figure 4, the shape of the 

 frequency distribution was similar from quarter 

 to quarter, especially for males. 



Progressions of mean lengths were set up for 

 males and females as depicted in Figure 5. The 

 smallest blue marlin recruited into the fishery in 



the first quarter were females, with males being 

 recruited 1 yr later. Males were present in the 

 fishery for 3% yr and females for 7 yr. Several 

 age-groups represented by one or two individuals 

 were separated for both sexes. The existence of 

 these age-groups was tentatively accepted, but the 

 accuracy of their estimated mean lengths was 

 viewed with skepticism in calculating growth 

 parameters. The mean length estimates of male 

 and female age-groups were in close agreement 

 until about 250 cm {S = 0.50, P>Om). From 250 to 

 300 cm, the mean lengths for female age-groups 

 were larger than estimates for males. Above 300 

 cm, only female age-groups were found, and these 

 formed an irregularly increasing progression. 



Estimates of von Bertalanffy growth pa- 

 rameters for both sexes were first obtained using 



MALE 



Figure 4-Blue marlin length 

 composition by sex and 

 quarter for the analysis of 

 pooled data. The smooth 

 curves represent age-groups 

 separated by the computer 

 program ENORMSEP, and 

 circles represent observed 

 values. 



>- 



UJ 



O 



UJ 



n: 



>- 

 o 



z 



o 



FIRST QUARTER 



1 1 ' \ 1 : 1 r 



SECOND QUARTER "o 



100 150 200 250 300 350 



LENGTH INTERVAL (cm) 



100 150 200 250 300 350 400 450 



LENGTH INTERVAL (cm) 



564 



