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Fishery Bulletin 113(2) 
which also includes the genera Gymnammodytes and 
Hyperoplus, Ammodytes is diagnosed by the presence 
of scales deeply embedded in dermal plicae below the 
lateral line, a highly protrusible upper jaw (Pietsch, 
1984), and non-expanded neural and haemal spines 
on the caudal vertebrae (Ida et al., 1994). Six species 
currently are recognized in the genus Ammodytes: 2 in 
the eastern North Atlantic Ocean (A. tobianus Linnae- 
us, 1758, and A. marinus Raitt, 1934), 2 in the west- 
ern North Atlantic Ocean (A. americanus DeKay, 1842, 
and A. dubius Reinhardt, 1837), and 2 in the North 
Pacific Ocean (A. hexapterus Pallas, 1814, and A. per- 
sonatus Girard, 1856). All are very similar morpholog- 
ically, having an elongate body up to 280 mm in total 
length, scales aligned in dermal plicae for the length 
of the body, long dorsal and anal fins, and no pelvic 
fins. Species generally are distinguished by meristic 
characters and relative body depth. We focus primar- 
ily on the sand lances of the North Pacific Ocean and 
adjacent seas for the purpose of clarifying their sys- 
tematic status. 
The first species recognized in this genus was col- 
lected from Sweden to the Mediterranean and de- 
scribed by Linnaeus (1758) as A. tobianus. Of 2 other 
names published in this genus in the early 1800s, A. 
alliciens Lacepede, 1800, was designated an unneed- 
ed replacement name for A. tobianus, and A. cicerelus 
Rafinesque, 1810, was allocated to Gymnammodytes as 
a valid species (Eschmeyer, 2013). In the North Pacific 
region, the first species described was A. hexapterus, 
from material collected or observed from off the Ka- 
mchatka Peninsula and Kuril Islands in Russia, the 
islands “between Asia and North America,” and the 
coast of North America (Pallas, 1814; Lindberg, 1937). 
Pallas (1814) compared it with the Atlantic species 
A. tobianus as described by Artedi (1738; Walbaum 
1792), noting that A. hexapterus had more numerous 
vertebrae. 
In his work on fishes collected during the Pacific 
railroad surveys of the early 1800s, Girard (1856) de- 
scribed A. personatus from Cape Flattery, Washing- 
ton. In 1873, Cope described A. alascanus from Sitka, 
Alaska, without comparing it with previously de- 
scribed species. Jordan (1906) referred all Ammodytes 
of the North Pacific region to Ammodytes personatus, 
including populations from Alaska to Monterey, Cali- 
fornia, and from Siberia to the Inland Sea of Japan. 
He made no comments on A. hexapterus and was un- 
certain about the status of A. alascanus, as well as of 
the northernmost populations of Ammodytes, suggest- 
ing that they may be referable to a circumboreal A. 
tobianus. Lindberg (1937) recognized differences be- 
tween Ammodytes off the coast of Japan and species 
from more northern areas, referring these populations 
in Japan to A. personatus, although much later he and 
Krasyukova (Lindberg and Krasyukova, 1975) synony- 
mized all nominal North Pacific species of Ammodytes 
under A. hexapterus. 
The last 2 species to be described from the North 
Pacific region were Ammodytes aleutensis and A. ja- 
ponicus of Duncker and Mohr (1939). They recognized 
A. aleutensis to be widely distributed from Unalaska 
in the eastern Aleutian Islands to Hokkaido in north- 
ern Japan and Nagasaki in southern Japan and A. 
japonicus to be only from the type locality of Otaru 
(=“Otaka”), Hokkaido, that also is included among 
the type localities of A. aleutensis. Duncker and Mohr 
(1939) distinguished A. japonicus from A. aleutensis 
on the basis of its fewer dorsal-fin rays and higher 
number of dermal plicae. In addition, they observed 
that, in their specimens of A. japonicus, the origin 
of the dorsal fin was farther posterior (posterior half 
versus middle of pectoral fin) and the ventrolateral 
fold was shorter (extending to mid-anal fin versus the 
posterior third of the anal fin and beyond). Although 
Andriashev (1954) noted the presence of significant 
variation among more southern forms and the need 
for additional taxonomic work, he recognized 2 species 
of Ammodytes across northern seas: A. tobianus in the 
Atlantic Ocean and A. hexapterus from the Barents 
Sea to the Baltic Sea. Within A. hexapterus, he recog- 
nized the subspecies A. hexapterus marinus from the 
Barents Sea to the Baltic Sea and A. hexapterus hexa- 
pterus in the North Pacific region. 
The number of species of Ammodytes in waters 
off Japan has been in question for the last century. 
Ohshima (1950) examined the numbers of vertebrae 
in Ammodytes from 7 locations around Japan — in 
the Seto Inland Sea, southern and northern Japan 
on the Pacific Ocean side, the northern tip of Hon- 
shu, and the northcentral Kuril Islands — and found 
differences in vertebral numbers. Lindberg and Kra- 
syukova (1975) noted confusion in use of the names 
A. hexapterus and A. personatus, as well as the un- 
certain status of A. aleutensis and A. japonicus, and 
proposed the synonymy of all northern Ammodytes 
within A. hexapterus, including those species in the 
western North Pacific region around Japan. Kitaguchi 
(1979) also examined meristic data and found that 2 
species, which he identified as A. personatus and A. 
hexapterus, occurred together in the area around Wak- 
kanai in the Soya Strait off northeastern Hokkaido. In 
their study of the life history characteristics of Ammo- 
dytes, Hashimoto and Kawasaki (1981) concluded that 
2 populations were included in “A. personatus” col- 
lected from the Pacific Ocean coast of northern Japan 
(Tohoku district) on the basis of meristic and allozyme 
analyses. Later, Hashimoto (1984) expanded his study 
of meristics within Ammodytes, examining material 
from several localities around Japan, and concluded 
that 3 genetically independent but geographically 
overlapping subspecies were likely present around 
Japan. 
No comprehensive genetic studies of sand lanc- 
es of the North Pacific Ocean and surrounding seas 
have been conducted; however, several regional stud- 
ies have been published. An allozyme study compared 
populations around Japan with one sample from Ko- 
diak Island, Alaska, and described 3 non-interbreeding 
groups that were living sympatrically around Japan; 
i 
