Evseenko and Bolshakova: Late and transformation stages of larvae of the Diaphus ostenfeldi in the South Pacific Gyre 321 
a steep profile; the depth of the head at the corner of the 
mouth is almost equal to HL. The jaws are long and con- 
tinue beyond the vertical of the eye posterior edge; both 
jaws have small teeth. Jaw length increases with larval 
size. The snout is short (SnL 19-22% HL), the eye is slightly 
oval at sizes up to about 16 mm SL (ED 25-30% HL). The 
anus opens slightly behind the midbody (PAL 57-61% SL). 
The dorsal fin begins almost at the middle of the body (PDL 
4448% SL). The posterior margin of the pectoral fin rays 
reaches the vertical of the ventral fin base, and the tips of 
the ventral fin rays reach the anal fin origin. The propor- 
tions are generally retained with increases in larval size. 
CMOOM oe 
Meristic characters 
D: 16-17, A: 16, P,: 11, P,: 8, C: 6—-10+9-6(5), GR: 
(8)9+14+15—-17=25-26, V: 37-38. Fin rays are formed in all 
fins at 8.6 mm SL, and larvae have a definitive number of 
gill rakers at 12.0 mm SL. Larvae have 37-38 myomeres. 
Pigmentation 
The 8.6-mm-SL larva (Fig. 2A) has one melanophore dor- 
sally on the peritoneum near the terminus of the gut, one 
melanophore behind the anal fin base (these melanophores 
Ny WN WSS — —. 
Figure 2 
Illustrations of 5 larval and transformation specimens of Diaphus ostenfeldi caught in the southwestern 
Pacific Ocean in 1985: (A) 8.6 mm standard body length (SL), (B) 9.5 mm SL, (C) 10.7 mm SL, (D) 10.7 mm 
SL (dorsal view), (E) 10.7 mm SL (ventral view), (F) 15.8 mm SL, and (G) 20.5 mm SL. 
