320 
Fishery Bulletin 118(4) 
3054, and 3069) during the 34th expedition of the RV Dmi- 
try Mendeleev to the southwestern Pacific Ocean in Jan- 
uary—February 1985 (Fig. 1). All specimens were caught 
by using an Isaacs-Kidd mid-water trawl with the Samy- 
shev-Aseev modification in the depth layers of 0-100 m, 
0-200 m, and 0-600 m in the area between 35°S and 57°S. 
This trawl is 25 m long and has a 5-mm mesh net without 
nodes and with a terminal insertion of 500-ym nylon mesh 
and a 6-m” mouth area. The specimens were preserved and 
stored in 10% formaldehyde. We captured 62 specimens 
that were 8.6—20.5 mm standard body length (SL); larvae of 
smaller sizes were absent in samples of trawl hauls. 
Information for the following features are included in 
the descriptions of larval stages in this paper (Moser, 
1996): SL, head length (HL), body depth at pectoral fin 
base (BD), preanal length (PAL), predorsal length (PDL), 
snout length (SnL), horizontal diameter of the eye (ED), 
number of rays in dorsal fin (D), number of rays in anal 
fin (A), number of rays in pectoral fin (P,), number of rays 
in pelvic fin (P,), number of rays in caudal fin (C), number 
of gill rakers (GR) on the upper and lower parts of the 
first gill arch, and number of vertebrae (V). Descriptions 
include patterns of the following photophores (Bekker, 
1983): branchiostegal (Br), opercular (Op), pectolateral 
(PLO), pectoventral (PVO), pectoral (PO), ventrolateral 
(VLO), ventral (VO), supraanal (SAO), anterior anal 
(AOa), posterior anal (AOp), and posterolateral (Pol). Also 
included in descriptions are the following orbital glands: 
dorsonasal (Dn), anteorbital (Ant), suborbital (So), and 
ventronasal (Vn). 
Results 
Identification 
The identification of large specimens (>20 mm SL) as 
D. ostenfeldi was based on the following features: the num- 
ber of gill rakers on the first gill arch of 25-26, So absent, 
Ant present, Dn and Vn connected but not extended ante- 
riorly from the olfactory rosette, no enlarged teeth in the 
lower jaw inner row, head depth approximately equal to its 
length, VLO about midway between lateral line and base of 
the ventral fin. The identification of specimens smaller 
than 20 mm SL was based on tracing characters from fully 
formed, large metamorphic specimens backward to smaller 
specimens. 
Body proportions 
The larvae have a moderately deep body (BD 24—28% SL). 
The head is relatively small (HL 25-30% SL) but deep with 
Pacific Ocean 
© 3051 03070 
@ 3050 
ana 10) 304° 
Oia @ 3045-3046 STFZ 
@ 3057-3059 
@ 3010-3042 Oa) 
©3009 
N © 3061 
@ 3008 L50°S 
©3007 
0 3006--- ~~ 
_- - 7 03005 
180°W 165°W 150°W 135°W 120°W 
Figure 1 
Schematic map of the stations (open circles) where larval (open squares) and adult (black 
circles) Diaphus ostenfeldi were sampled during the 34th cruise of the RV Dmitry Men- 
deleev in the southwestern Pacific Ocean between January and February 1985. Dashed 
lines indicate the positions of biogeographic borders (Becker and Evseenko, 1986) for the 
central water mass (C), periphery of the central water mass (P), subtropical frontal zone 
(STFZ), notal zone (N), Antarctic Polar Frontal Zone (APFZ), and Antarctic (A). Station 
numbers are given next to station markers. 
