Length of maxillary — tip of mandible to posterior 

 end of maxillary bone. 



Maximum body depth — base of dorsal groove to 

 edge of pelvic groove, in the transverse plane where 

 this measurement is maximum (usually near base of 

 pectorals). 



Depth at vent — depth of body as described above 

 except in the transverse plane through vent. 



Length of pectoral fin — from base of first pectoral 

 fin ray to tip of longest ray with fin folded against 

 body. 



Length of pelvic fin — from base of fin rays to tip 

 when fin is held at slight angle from body. 



Dorsal fin height — from base of first dorsal fin 

 spine to tip of anterior lobe of first dorsal fin with fin 

 held as nearly erect as possible (see previous sec- 

 tion). 



METHODS OF ANALYSIS 

 Meristic Characters 



Counts of second dorsal and second anal fin rays 

 were the only meristic characters used. It was quite 

 evident early in the study that the number of fin rays 

 did not vary significantly with fish size, at least for 

 sizes of fish we examined, and that the number for a 

 species varied within a narrow range of two to four 

 rays (Table 2). The meristic characters were there- 

 fore eliminated from any further analyses. 



BLUE MARLIN 



>- 

 u 



Z 7 

 UJ 



a 6 



Ui 



tr 



-1 — i — i — i — i — i — i — i — i — i — i — i — i — i — i — i — i — i — i — i — r 



Mazatlan 



n x 



•F 22 209.0 



_1 1 I I I 1 I I I I 3L_1 I I I I I I L_i I I 1_ 



Buena Vista 

 j 



•F 35 205.7 



' V i I I I tLi i i I I i L^i i I i I i i— i-'' i 



ISO 160 170 110 190 200 310 220 230 240 250 260 

 155 165 175 1S5 1*5 205 215 225 235 245 255 265 



EYE-FORK LENGTH (cm) 



Figure 1. — Length frequency of blue marlin sampled in 

 this study. 



Morphometric Characters 



Linear regression and analysis of covariance were 

 the procedures used to analyze the data. Except for 



Table 3. — Equations for converting fork and mandible-fork lengths to eye-fork length. 

 Equations are based on Y = a + bX. 













Range of X 



Relation 



a 



b 



N 



r 



(cm) 



Blue marlin 













Eye-fork length on fork length 



-15.785 



0.810 



21 



0.997 



221.1-347.3 



Eye-fork length on 













mandible-fork length 



-5.105 



0.893 



22 



0.979 



194.0-297.6 



Sailfish 













Eye-fork length on fork length 



6.802 



0.714 



35 



0.926 



183.0-260.0 



Eye-fork length on 













mandible-fork length 



2.637 



0.852 



35 



0.940 



155.5-225.0 



Fork length on eye-fork length 



24.677 



1.200 



35 



0.926 





Striped marlin 













Eye-fork length on fork length 



-1.319 



0.745 



127 



0.745 



178.5-268.8 



Eye-fork length on 













mandible-fork length 



1.306 



0.840 



125 



0.985 



151.6-238.2 



110 



