making the measurement difficult to make witii any 

 accuracy. Ueyanagi and Yabe (1959) used this 

 measurement in their description of the blue marlin. 

 From these measurements I calculated standard 

 length minus snout length and trunk length (stan- 

 dard length less head length). No meristic data were 

 taken because of the small size of the specimens. 

 Other data collected included the position of the 

 snout in relation to the center of the eye (whether 

 the snout was above, equal, or below a plane pas- 

 sing along the body axis through the center of the 

 eye), the position of the pterotic spine (whether it 

 was nearly parallel to the body axis or whether is 

 projected upward at a 45° angle). This character 

 was suggested to me by Dr. Ueyanagi (pers. 

 comm.) as a possible means for separating striped 

 marlin (parallel to the body) from sailfish (project- 

 ing upward). The remaining data collected con- 

 cerned the number and location of chromatophores 

 on the lower jaw. gular membrane, and branchios- 

 tegal membrane. First, the extent of pigmentation 

 along the ramus of the lower jaw was noted, particu- 

 larly whether this pigment was confined to the tip of 

 the lower jaws or whether it extended posteriorly 

 along '/3. Vi. %, or Ys of the distance of the lower 

 jaw. In instances where this pigment varied from 

 left to right side, the greatest value was used. The 

 number of pigment cells occurring on the gular area 

 was counted. These cells were always on the mid- 

 line and variations of none, one, two, three, or more 

 than three, were observed. Cases of more than 

 three cells appeared as a distinct row along the mid- 

 line and were noted as a row. Number and location 

 of pigment cells on the branchiostegal membrane 

 were also noted. In all but one specimen having 

 branchiostegal membrane pigment, one cell occui- 

 red anteriorly on the midline. The one unusual 

 specimen had one cell slightly displaced to the left. 

 These variations of pigment are shown in Figure 1. 

 A rough analysis of the measurements produced 

 generally negative results. The purpose of these 

 analyses was to determine if more than one group 

 was visible from inspection of plotted values. The 

 only plots which did show differences were those 

 involving the length of the snout. I show one such 

 plot (Fig. 2) where the eye diameter divided by 

 snout length and expressed in percent is plotted 

 against standard length minus snout length. Speci- 

 mens greater than 9 mm in standard length (greater 

 than 7.5 mm in standard length minus snout length) 

 showed separation into two groups. The 10 speci- 

 mens with values greater than 75 percent included 



Ramus of lower jaw 

 Gular membrane 



Branchiostegal 

 ray 



and 

 membrane 



Chromatophore on tip of 

 lower jaw 



Chromatophore on 

 midline of gular 

 membrane 



Chromatophore 

 on branchi- 

 ostegal 

 membrane 



Figure I. — Diagramatic sketches of the pigment pattern 

 on the lower jaw, gular and branchiostegal membrane of 

 young istiophorids. a. Pigment pattern exhibits 

 chromatophores concentrated on the tip of the lower jaw, 

 one chromatophore on the posterior edge of the gular 

 membrane midline, and no chromatophores on the bran- 

 chiostegal membrane, b. Pigment pattern exhibits 

 chromatophores extending along '/i the length of the left 

 and right rami of the lower jaw. a row of cells on the 

 midline of the gular membrane, and no chromatophores on 

 the branchiostegal membrane, c. Pigment pattern exhibits 

 chromatophores extending along % the length of the lower 

 jaw rami, one cell on the posterior edge of the gular mem- 

 brane midline, and one cell on the midline of the branchio- 

 stegal membrane, d. Pigment pattern exhibits chromato- 

 phores extending along 7ti of the length on the right rami 

 and along Vi of the length of the left rami of the lower jaw, 

 one cell on the midline of the gular membrane, and one cell 

 on the branchiostegal membrane. 



three blue marlin identified by Ueyanagi and seven 

 specimens from my collections. These 10 have short 

 snouts and I feel confident that they are blue marlin. 

 In other plots which involved snout length, these 10 

 specimens were obviously different. I then ex- 

 amined the additional data from these 10 specimens 

 to see if they shared any other character. Eight of the 

 10 lacked gular pigment; the other two (a 10-mm 

 specimen provided by Ueyanagi and a 12.1-mm 

 specimen from my Miami material) each had one 



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