146 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



approximately the 25th ray) ; the anal fin has 22 

 rays; the pectoral fin is quite angular; and the 

 pelvic fins have elongated. Pigment is present 

 on lower middle portion of the dorsal fin. 



SAILFISH LARVA, 11.3 MILLIMETERS 



(Fig. 9) 



The snout has elongated, but there has been a 

 corresponding elongation of the mandible, and 

 the snout extension remains unchanged. The 

 diameter of the eye is approximately one-quarter 

 the head length (one-third on the previous speci- 

 mens). The keel on the face of the preopercle is 

 damaged so that no serrations are evident. The 

 dorsal fin has 50 rays, the anal fin 22 rays, and the 

 pectoral fin 18 rays (the full complement of rays 

 has been reached in these 3 fins). The pelvic 

 fins are slightly shorter on this specimen. A 

 groove for the pelvic fins has appeared as an 

 indentation of the belly. 



SAILFISH LARVA, 14.6 MILLIMETERS 



(Fig. 10) 



There is marked elongation of the snout and 

 extension beyond tip of mandible. The teeth 



are more numerous, with those on the lower jaw 

 more closely set than those on the upper. There is 

 a marked increase in height of dorsal fin, and the 

 the anal fin has 23 rays. A 3-toothed (or 3- 

 pronged) scale, arising from the pectoral girdle, 

 is situated on each side of the body just below the 

 tip of the pterotic spine. There is a general 

 increase in density of pigment. 



SAILFISH LARVA, 18.2 MILLIMETERS 



(Fig. 11) 



The snout is markedly produced (approximately 

 one-half the head length) and extends two-fifths 

 its length beyond the tip of the mandible. Teeth 

 are more numerous. The eye diameter is approxi- 

 mately one-fifth the head length. There is a 

 marked heightening in anterior portion of the 

 dorsal fin and a change in shape, and pelvic fins 

 have lengthened and a third ray has appeared 

 (constituting the full complement). A second 

 3-toothed scale is found on each side of the body 

 at the pectoral girdle. The caudal peduncle is 

 proportionately more slender. Pigmentation ex- 

 tends over the entire anterior portion of the 

 dorsal fin. 



Figure 9.— Sailflsh larva, 11.3 millimeters long (USNM 163333). 



^^Jr^S^ 



Figure 10.— Sailfish larva, 14.6 millimeters long. From Theodore N. Gill collections. 



