Orr et al. : Systematics of North Pacific sand lances of the genu sAmmodytes and description of a new species 
143 
Counts of precaudal 
of the North Pacific 
Table 7 
caudal, total vertebrae, and gill rakers of the lower arch in 
region that were analyzed in this study. 
specimens of species of Ammodytes 
Precaudal vertebrae 
36 
37 
38 
39 
40 
41 
42 
43 
44 
45 
46 
47 
48 
49 
n 
A hexapterus 
1 
2 
14 
32 
52 
19 
9 
3 
132 
A. personatus 
2 
9 
52 
80 
66 
51 
25 
9 
1 
295 
A. japonicus 
1 
12 
9 
27 
33 
18 
6 
1 
108 
A. heian n. sp. 
2 
5 
1 
9 
6 
23 
Caudal vertebrae 
21 
22 
23 
24 
25 
26 
27 
28 
n 
A hexapterus 
1 
6 
22 
34 
46 
18 
5 
113 
A. personatus 
3 
9 
50 
103 
89 
35 
6 
295 
A. japonicus 
5 
23 
43 
23 
8 
3 
2 
107 
A. heian n. sp. 
2 
6 
14 
1 
23 
Total vertebrae 
59 
60 
61 
62 
63 
64 
65 
66 
67 
68 
69 
70 
71 
72 
73 
n 
A hexapterus 
2 
6 
26 
44 
35 
16 
3 
1 
133 
A. personatus 
2 
16 
43 
62 
61 
42 
39 
27 
4 
296 
A. japonicus 
1 
3 
16 
29 
45 
18 
5 
1 
117 
A. heian n. sp. 
2 
7 
2 
10 
2 
23 
Lower gill rakers 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
26 
n 
A hexapterus 
4 
12 
33 
14 
7 
2 
72 
A. personatus 
1 
1 
23 
54 
64 
48 
13 
11 
1 
217 
A. japonicus 
2 
9 
12 
25 
19 
5 
2 
3 
4 
1 
82 
A. heian n. sp. 
1 
2 
5 
9 
5 
1 
23 
21% HL vs. 11-15% HL), more total vertebrae (65-72 
vs. 63-67) and precaudal vertebrae (40-47 vs. 39-43), 
fewer pored lateral line scales (121-152 vs. 142-185) 
and dermal plicae (143-172 vs. 156-198), and fewer 
pigmented pectoral fin rays (2-6 vs. 4-10). This species 
is distinguished from A. personatus and all other spe- 
cies of the North Pacific region by a unique COI haplo- 
type (GenBank Accession KJ137280; Appdx. 2). 
Description 
Body elongate, slender, depth at dorsal-fin origin 
27.5- 56.9% HL (43.6% HL), depth at anal-fin origin 
28.0-55.4% HL (39.3% HL), depth at caudal peduncle 
9.5- 15.3% HL (12.0% HL). Head long, 18.7-22.2% SL 
(21.7% SL). Snout long, 23.0-30.0% HL (26.9% HL). 
Mouth large: upper jaw 27.0-36.0% HL (30.9% HL); 
lower jaw 36.0-50.0% HL (43.3% HL). Orbit moder- 
ately large, 12.0-21.0% HL (18.2% HL). Gill rakers 
long, slender, 4-6 (5) on upper part of arch, 20-25 (23) 
on lower part, 25-30 (28) total, longest raker length 
7.4-12.7% HL (11.3% HL). Pseudobranchs 9-16 (11). 
Pored lateral-line scales 121-152 (125). Scales be- 
low lateral line situated along 143-172 (149) oblique 
dermal plicae. 
Dorsal-fin rays 56-63 (59). Anal-fin rays 27-33 (30), 
7-14 (9) pterygiophores anterior to first caudal verte- 
bra. Pectoral-fin rays 13-16 (15), rays 2-6 (4) pigment- 
ed. Total vertebrae 65-72 (68), precaudal vertebrae 
40-47 (44), caudal vertebrae 21-27 (24). 
Distribution 
On the basis of material examined, we determined that 
Ammodytes hexapterus ranges from the Soya Strait off 
Wakkanai, Hokkaido, Japan, through the Sea of Ok- 
hotsk, the western and northeastern Bering Sea, and 
into the Chukchi Sea (Fig. 1). In the eastern Bering 
Sea, its range overlaps with that of A. personatus south 
to Norton Sound, the Pribilof Islands, Kuskokwim Bay, 
