470 
PACIFIC SCIENCE, Vol. XV, July 1961 
standard length of about 27 mm. and before 
it attains 35 mm. An additional juvenile char- 
acter of the smaller specimen is the short, fleshy 
pectoral fin. 
The larger of the 2 Hawaiian specimens dif- 
fers from all others of the genus Argyripnus in 
two rather important characters, the position of 
the anal origin in front of the dorsal origin, 
and the abdominal count of 11 IV. The IV pho- 
tophores number (6) + (10) = 16 in almost 
all known specimens of the genus, the only ex- 
ceptions being found on 2 western Atlantic spe- 
cimens in which the counts are (6/7) + (10) 
= 16/17 and (6) + (9/10) = 15/16. Both of 
the Hawaiian specimens are otherwise very close 
to, and probably identical with, A. atlanticus 
Maul, a species hitherto known only from the 
North Atlantic. In Pacific species (A. ephip- 
piatus Gilbert and Cramer, A. iridescens Mc- 
Culloch, and an unrecorded specimen from the 
Philippines) the^anal origin is situated below 
the end of the dorsal fin. In A. atlanticus it is be- 
low the anterior rays of the dorsal and the anal 
origin of the younger Hawaiian specimen is 
similar. The fact that the two little Hawaiian 
fishes differ from one another in this character 
suggests that the anal position may be somewhat 
variable. In meristic characters these specimens 
differ from A. atlanticus only in the number of 
photophores in the first VAV-AC group and, as 
noted above, these photophores are probably not 
fully developed on the Hawaiian fishes. If a few 
more photophores are still to appear in this 
series, both the VAV-AC and the IC counts would 
be within the range of the same counts of A. 
atlanticus. Evidence that a few more photo- 
phores actually are present in the adult is shown 
by the fact that the distance between the AC 
groups is proportionately greater than in any 
other specimens of the genus known ( see Table 
3). 
These specimens are also like A. atlanticus 
and unlike other species in the lower and less 
abrupt curve in the VAV-AC series above the 
front of the anal fin. Their more slender bodies 
can certainly be attributed to their youth and 
the relative lengths of the trunk and tail prob- 
ably also change with age. Both of the young 
Hawaiian fishes have a proportionately longer 
tail, shorter trunk, and shorter distance between 
the snout and ventral bases than are found in 
older specimens from either the Atlantic or Pa- 
cific oceans. 
TABLE 1 
Meristic Characters of Argyripnus Species 
SPECIMENS 
STAND- 
ARD 
LENGTH 
DOR- 
SAL 
RAYS 
ANAL RAYS 
PEC- 
TORAL 
RAYS 
VEN- 
TRAL 
RAYS 
GILL RAKERS ON 
FIRST ARCH 
A. atlanticus, juv. 
Hawaii 
21-21 A 
11-12 
19+5-6=24-25 
A. atlanticus, juv. 
Hawaii 
35.5 
11 
15+10=25 
18 
_ 
19+6=25 
A. atlanticus, type 1 
eastern Atlantic 
56 
12 
— =27 
19 
7 
17+7=24 
A. atlanticus 
western Atlantic 
55-71 
11-12 
13-1 5 + (8)9-10=22-27 
(16)17-19 
6-7 
17-19+6-7=22-26 
A, ephippiatus 
Hawaii 
72 
12 
12+12=24 
15 
6? 
13-14+5=18-19 
A. ephippiatus, type 
Hawaii 
75 
11 
11 + 11=22 
15 
_ 
14+5 = 19 
A. ephippiatus 
Hawaii 
80 
11-12 
15 
_ 
13+5-6=18-19 
A. iridescens 2 Australia.... 
90-135 
12-14 
- = 24-25 
16-17 
7 
16+?=? 
Argyripnus sp. 
Philippines 
82 
12 
13 + 12=25 
17 
7 
12+4=16 
1 Data from Maul, 1952: 56. 
2 From McCulloch, 1926: 169, and Norman, 1930: 299. 
