Bolshakova et al.: Morphology of larvae of 6 Lampanyctus species in the central South Pacific Ocean 119 
L. intricarius are similar in pigmentation to larvae of Lam- 
panyctus cf. L. photonotus (Moser and Watson, 2001) from 
the western Atlantic Ocean and differ from them in body 
proportions. Differences between larvae of L intricarius and 
of Lampanyctus cf. L. photonotus are found in body depth, 
head length, and diameter of the eye. 
Morphology In our collections, 102 larvae with sizes of 6.9— 
20.4 mm SL were found. The larvae from the collections of the 
34th expedition of RV Dmitry Mendeleev have been described 
in detail previously (Bolshakova and Evseenko, 2015). 
Photophore formation All larvae 6.9—-20.4 mm SL have 
only Bro. 
Pigmentation See Bolshakova and Evseenko (2015). 
Meristic characters D: 15-16, A: 18—20, P,: 13-14, P,: 7-8, 
C: 6+10—9+6, GR: 4+1+(9)10, V: 38-39, BrR: 8. 
Distribution Larvae of L. intricarius were collected at 
9 stations (st. 3042, 3043, 3044, 3049, 3050, 3052, 3054, 
3057, and 3068) between 37°S and 46°S in the notal zone 
and in the subtropical frontal zone of the South Pacific 
Ocean (Fig. 2A). 
Lampanyctus sp. D (sensu McGinnis, 1982) 
Distinguishing features The main feature of the larvae of 
this species is the almost complete absence of pigment 
on the body. Pigmentation is present in all larvae only in 
the head region above the brain and above the terminal 
gut section. A lack of or a small amount of pigment on the 
body is also noted for the larvae of L. nobilis, the slender 
lanternfish (LZ. tenuiformis), and L. idostigma. Larvae of 
L. nobilis have a row of melanophores on the istmus. Lar- 
vae of L. tenuwiformis have one melanophore anterior to the 
anus and have a blunt snout. Larvae of L. idostigma have 
no melanophores above the brain. 
Morphology In our collections, 110 larvae with sizes of 
7.2-17.0 mm SL were found (Figs. 6 and 7). Larvae have 
relatively slender bodies (BD 24-29% SL) with large heads 
(HL 27-33% SL). Eyes are round and large (ED 24-34% 
HL) and decrease in proportion to body size during devel- 
opment. The jaws reach the vertical of the eye posterior 
margin in large larvae (SnL 26% HL), and there are teeth 
on both jaws. The dorsal fin originates near the middle 
of the body (PDL 47-56% SL). The anus opens behind 
the middle of the body (PAL 58-65% SL). Metamorphosis 
occurs at a size >17.0 mm SL. 
Meristic characters D: 13-15, A: 16-17, P,: 13-14, P,: 8, C: 
6+10—-11+5, GR: 4(5)+1+10, V: 35-36, BrR: 8. All the rays in 
the fins are distinguishable in the 10.3-mm-SL larva, and 
the number of gill rakers is definitive in the 13.0-mm-SL 
larva. 
Pigmentation The pigmentation of larvae varies consid- 
erably, even among larvae of the same size from the same 
sample. The pigmentation that is present in almost all 
studied larvae includes the following: inner melanophores 
Figure 6 
Illustrations of 2 early developmental stages of larval Lampanyctus sp. D caught in the 
central South Pacific Ocean in 1985 (A) at station 3042 (9.7 mm standard body length 
[SL]) and (B) at station 3049 (12.5 mm SL). 
