Bull. Natl. Mus. Nat. Sci., Ser. A, Suppl. 6, pp. 17–26, March 30, 2012

Glossanodon microcephalus, a New Argentine Fish from Japan and
the South China Sea (Protacanthopterygii: Argentinidae)
Hiromitsu Endo1 and Kazuya Nashida2
1

Laboratory of Marine Biology, Faculty of Science, Kochi University,
2–5–1 Akebono-cho, Kochi 780–8520, Japan
E-mail: endoh@kochi-u.ac.jp
2
Kochi Kuroshio Research Laboratory, National Research Institute of Fisheries Science, Fisheries
Research Agency (FRA), 6–1–21 Sanbashi-dori, Kochi 780–8010, Japan
E-mail: knashi@affrc.go.jp

Abstract A new argentinid species, Glossanodon microcephalus, is described based on 30 specimens (53–97 mm SL) from Tosa Bay, off Kochi Prefecture, Shikoku Island, southern Japan, andfrom the southwest South China Sea. The new species clearly differs from its congeners in having
the following combination of characters: dorsal-¿n rays 11–12; anal-¿n rays 10–12; pectoral-¿nrays 17–19; pelvic-¿n rays 10–12; branchiostegal rays 5; gill-rakers on ¿rst arch 27–30; vertebrae
44–46; small conical teeth in 1–2 and 1–3 irregular rows on vomer and palatines respectively;
10–21 small conical teeth on lower jaws, and 3–7 on tip of tongue; head length 25–27% SL; snout
length 30–33% HL; anus immediately anterior to anal-¿n origin; a longitudinal black stripe above
lateral line interrupted, alternately composed of short bars and faint blotches; dense pigmentation
just behind chin; no melanophore on isthmus to abdomen; maturation at small size (the minimum
sizes of mature males and females are 65 mm SL and 72 mm SL respectively). The new species is abenthopelagic dweller on muddy and sandy bottoms in depths of about 100–200 m.
Key words: Argentinidae, Glossanodon, new species, Japan, South China Sea, precocious.

Argentines of the genus Glossanodon
Guichenot, 1867 are small benthopelagic ¿shes(attaining ca. 7–20 cm SL), occurring on offshore
bottoms and sea mounts of tropical to temperatewaters in world oceans (Kobilyansky, 1998). The
genus is composed of 14 known species, classi¿ed into two subgenera: Glossanodon Guichenot,
1867 and the monotypic Prosoarchus Cohen,
1958 containing Glossanodon pygmaeus Cohen,
1958 (Endo and Nashida, 2010). Further, the 13
species of the subgenus Glossanodon are tentatively divided into three species groups by Kobilyansky (1998), and one species recently
described by Endo and Nashida (2010): “polli”
group (8 species), “leioglossus” group (2 species), and “lineatus” group (3 species). Of these,
three Japanese species, Glossanodon kotakamaru
Endo and Nashida, 2010, Glossanodon semifasciatus(Kishinouye, 1904), and Glossanodon lineatus(Matsubara, 1943) belong to the “polli” group,“leioglossus” group, and “lineatus” group respectively.
During bottom trawl surveys by the R/V
Kotaka-maru in central Tosa Bay from 2007 to
2010, and from sampling at the Mimase ¿sh market of Kochi City in March of 2010, we obtained
about 100 small specimens of a Glossanodon
species (46–97 mm SL). While somewhat similar
to the young of G. semifasciatus, they differ fromtheir congeners in having a smaller head, ashorter snout, an interrupted longitudinal dark
stripe above the lateral line, and lower counts ofall ¿n-rays, gill-rakers, and vertebrae. In addition, most specimens about 70 mm SL and larger
were mature, suggesting that this is a small Glossanodon species. Subsequent to collecting thespecimens, we found three specimens of Glossanodon (72–78 mm SL) deposited in the ¿sh18

H. Endo and K. Nashida

Fig. 1. Map showing two localities of Glossanodon
microcephalus sp. nov.

collection of Kochi University (BSKU) that werecollected by the R/V Hakuho-maru from theSouth China Sea in 1972 (Fig. 1). These subsequent specimens were considered conspeci¿cwith the specimens recently collected from Tosa
Bay and from the Mimase ¿sh market, and weherein describe this new species.
Materials and Methods
Specimens examined are deposited in the following institutions: Australian Museum, Sydney(AMS); Laboratory of Marine Biology, Facultyof Sciences, Kochi University (BSKU); National
Museum of Nature and Science (NSMT, formerly National Science Museum, Tokyo). Otter
trawls by the R/V Kotaka-maru (NRIFS:National Research Institute of Fisheries Science,
Japan) in central Tosa Bay were planned andoperated by K. Nashida (NRIFS).
Counts and measurements follow Cohen(1958) and Kobilyansky (1998), which were discussed by Endo and Nashida (2010). Proportionsin the diagnosis and description are based on 24
adult specimens ranging from 72–97 mm SL. The
longest ray of each ¿n was not measured becauseof damaged (lacking) distal sections except in a
few specimens. Observation of dentition andbony elements were made by Alizarin Red S

Fig. 2. Glossanodon microcephalus sp. nov., NSMT-P
106647, holotype, 97 mm SL in fresh (above andmiddle) and in preserved (below) condition. Photographed by N. Nakayama (above and middle) and
H. Endo (below).

stained specimens except in the holotype. Total
length, standard length, and head length areabbreviated as TL, SL, and HL respectively. Finrays and vertebrae were counted from radiographs.
Glossanodon microcephalus sp. nov.
(New English name: Small-head argentine)(New Japanese name: Tsumari-nigisu)(Figs. 2–7, Tables 1–3)
Glossanodon semifasciatus (not Kishinouye, 1904): Takagi et al., 2010: 179 (photograph of fresh specimen
trawled off southwest of Shikoku, landed at Fukaura¿shing port, Ainan-cho, Ehime, Shikoku Island,
Japan).

Holotype. NSMT-P 106647 (formerly BSKU
103750), 97 mm SL, female, Tosa Bay,
33°18.3ƍN, 133°36.9ƍE–33°19.7ƍN, 133°38.1ƍE,
120–116 m, R/V Kotaka-maru, bottom trawl, St.

New Glossanodon from Northwestern Paci¿cT1ƍ-1, coll. by K. Nashida and K. Kenmotsu, 6
July 2010.
Paratypes. 29 specimens. Tosa Bay (27 specimens): AMS I. 45674-001 (formerly BSKU
104074, BSKU 104075), 88 mm SL, female,
89 mm SL, male, 33°18.39ƍN, 133°36.25ƍE–
33°16.85ƍN, 133°34.08ƍE, 120–122 m, R/V
Kotaka-maru, bottom trawl, St. T1ƍ-1, coll. by K.
Nashida and K. Kenmotsu, 8 Mar. 2010; BSKU
90672 (stained), 64 mm SL, female, 33°16.45ƍN,
133°32.77ƍE–33°15.27ƍN, 133°31.60ƍE, 119–122
m, R/V Kotaka-maru, bottom trawl, St. T1ƍ-2,
coll. by K. Nashida and N. Nakayama, 13 June
2007; BSKU 90673 (stained), 66 mm SL, female,
33°13.86ƍN, 133°34.35ƍE–33°12.60ƍN, 133°32.56ƍE,
149–151 m, R/V Kotaka-maru, bottom trawl, St.
T3-2, coll. by K. Nashida and N. Nakayama, 13June 2007; BSKU 92320, 91 mm SL, male,
BSKU 92321, 73 mm SL, female, BSKU 92323,
93 mm SL, female, 33°13.85ƍN, 133°34.30ƍE–
33°12.63ƍN, 133°32.25ƍE, 148–156–143 m, R/V
Kotaka-maru, bottom trawl, St. T3-2, coll. by K.
Nashida and N. Nakayama, 23 Aug. 2007; BSKU
101347, 77 mm SL, male, BSKU 101348, 59 mm
SL sex unknown, BSKU 101349, 81 mm SL,
female, 33°18.15ƍN, 133°35.86ƍE–33°16.98ƍN,
133°33.54ƍE, 120–119 m, R/V Kotaka-maru, bottom trawl, St. T1ƍ-1, coll. by K. Nashida and S.
Yamamoto, 16 Nov. 2009; BSKU 102586,
88 mm SL, male, 33°18.42ƍN, 133°36.28ƍE–
33°17.19ƍN, 133°34.17ƍE, 120–121 m, R/V
Kotaka-maru, bottom trawl, St. T1ƍ-1, coll. by
K. Nashida and S. Yamamoto, 15 Jan. 2010;
BSKU 102896, 82 mm SL, male, 33°17.78ƍN,
133°35.49ƍE–33°16.34ƍN, 133°34.40ƍE, 121–
123 m, R/V Kotaka-maru, bottom trawl, St. T
1ƍ-1, coll. by K. Nashida and K. Kenmotsu, 15
Apr. 2010; BSKU 104068, 87 mm SL, female,
BSKU 104069, 85 mm SL, female, BSKU
104070, 89 mm SL, female, BSKU 104071,
92 mm SL, female, BSKU 104072, 96 mm SL,
female, BSKU 104073, 85 mm SL, male, samedata as AMS I. 45674-001; BSKU 104076,
83 mm SL, male, BSKU 104077, 85 mm SL,
male, BSKU 104078, 81 mm SL, male, BSKU
104079, 88 mm SL, male, 33°18.39ƍN,19

Fig. 3. Glossanodon microcephalus sp. nov., BSKU
17163, paratype, 75 mm SL, male, in preserved
condition. Photographed by H. Endo.

133°36.25ƍE–33°16.85ƍN, 133°34.08ƍE, 120–122m, R/V Kotaka-maru, bottom trawl, St. T1ƍ-1,coll. by K. Nashida and K. Kenmotsu, 8 Mar.
2010; BSKU 104080, 89 mm SL, female, BSKU
104081, 91 mm SL, female, BSKU 104082,
76 mm SL, male, BSKU 104083, 72 mm SL,
female, 33°18.0ƍN, 133°35.2ƍE–33°17.0ƍN, 133°33.3ƍE,118–118 m, R/V Kotaka-maru, bottom trawl, St.
T1ƍ-1, coll. by K. Nashida and K. Kenmotsu, 1June 2010; NSMT-P 106648 (formerly BSKU
101346), 85 mm SL, male, same data as BSKU
102586; NSMT-P 106649 (formerly BSKU
102588), 53 mm SL, sex unknown, same data as
BSKU 103286. South China Sea (2 specimens):
BSKU 17162, 78 mm SL, female, BSKU 17163,
75 mm SL, male, 06°51.6ƍN, 108°47.2ƍE–06°51.6ƍN,108°48.9ƍE, 137–135 m (shelf edge), R/V
Hakuho-maru (KH-72-1), St. 50, beam trawl,coll. by O. Okamura, 10–11 July 1972.
Non-types. 72 specimens. Tosa Bay: BSKU
101349, 82 mm SL, female, same data as NSMTP 106648; BSKU 102672, 88 mm SL, male,central Tosa Bay, 120 m, R/V Kotaka-maru,
bottom trawl, St. T1ƍ-1, coll. by K. Nashida, 12
Feb. 2010; BSKU 104187, 87 mm SL, male,
33°18.7ƍN, 133°36.7ƍE–33°19.6ƍN, 133°38.2ƍE,
120–116 m, R/V Kotaka-maru, bottom trawl, St.
T1ƍ-1, coll. by K. Nashida and K. Kenmotsu, 1
Sept. 2010; BSKU 104223 (stained), 65 mm SL,
male, BSKU 104224 (stained and dissected),
93 mm SL, female, BSKU 104225 (stained),
84 mm SL, male, BSKU 104226 (stained),
86 mm SL, male, BSKU 104227 (stained),
90 mm SL, male, BSKU 104228 (10 stained
specimens), 81–95 mm SL, BSKU 106339 (21specimens), 74–95 mm SL, Mimase ¿sh market,

20

H. Endo and K. Nashida
Table 1. Counts, dentition and depth ranges of 4 Glossanodon species. Data from the followings: 1: —Cohen(1958), 2—Kobilyansky (1998), and 3—this study. Numbers of teeth on lower jaw in parentheses.
G. microcephalus

No. of specimens
SL (mm)Dorsal-¿n rays
Anal-¿n rays
Pectoral-¿n rays
Pelvic-¿n rays
Gill-rakers on 1st arch
Branchiostegal rays
Vertebrae
Lateral-line scales
Teeth on lower jaw
Teeth on tongue
Depth ranges (m)References

G. leioglossus

G. semifasciatus

G. pseudolineatus

30

4

32

5

53–97
11–12
10–12
17–19
10–12
27–30
5
44–46
44–45
entirely (10–17)
4–6
116–1563

51–111
13–14
11–13
20–22
12
36
5
49
—
partly (2–8)
2–3
80–3601

94–206
11–13
11–13
18–22
10–12
35–40
5
46–49
50–53
partly (0–10)
2–6
70–240
1, 3

72–80
10–11
10
18–19
11
24–26
4
43–44
—
entirely
2–3
150–1562

Kochi City, Kochi Prefecture, Japan, offshore
trawl by Kousei-maru, coll. by N. Nakayama and
M. Doi, 19 March 2010; BSKU 106340 (18specimens), 46–88 mm SL, same data as BSKU
104068; BSKU 106341 (11 specimens),
78–93 mm SL, males, BSKU 106342 (3 specimens), 90–93 mm SL, females, same data as
holotype. South China Sea: BSKU 17164, 72 mm
SL (damaged), male, same data as BSKU 17162
and BSKU 17163.
Diagnosis. A new species of Glossanodon
with the following combination of characters:
dorsal-¿n rays 11–12; anal-¿n rays 10–12; pectoral-¿n rays 17–19; pelvic-¿n rays 10–12; branchiostegal rays 5; gill-rakers on ¿rst arch 27–30;
vertebrae 44–46; small conical teeth in 1–2 and1–3 irregular rows on vomer and palatines
respectively; 10–21 small conical teeth on lower
jaw, and 3–7 on tip of tongue; head length25–27% SL; snout length 30–33% HL; anus
located immediately anterior to anal-¿n origin; alongitudinal black stripe above lateral line, interrupted, alternately composed of short bars andfaint blotches; anterior part of gular just behindchin densely pigmented; isthmus to thorax, andabdominal region unpigmented externally.
Description. Proportions and counts are shownin Tables 1–3. Data for the holotype are given inbrackets. Body slender, moderately deep, depth
at dorsal-¿n base about 13–14% SL, nearlysquare in cross-section at pectoral-¿n origin.
Dorsal-¿n origin above joint between 15th and16th vertebrae to middle of 16th vertebra[between 15th and 16th], predorsal length shorter
than postdorsal. First two dorsal ¿n-rays
unbranched, others bifurcated: 1st ray short(5.2% SL in NSMT-P 106648), slender, unsegmented; 2nd elongated (10.9% SL in BSKU
102586). Adipose ¿n slender, moderate in size,
origin located above middle of anal-¿n base.
Anal-¿n origin below 35th vertebrae. Dorsal-¿nbase somewhat longer than anal-¿n base. Caudal
peduncle moderately long, depth 57–68% oflength [57]. Pectoral ¿n positioned ventrolaterally, its base at an angle of about 35 degrees. Prepectoral length almost equal to HL. Pelvic-¿norigin below 6th dorsal-¿n ray and 18th vertebra;
anterior tip of pelvic girdle below 15th vertebra;
length from pectoral- to pelvic-¿n origins shorter
than that from pelvic to anal ¿n. Caudal ¿nforked.
Head small, length 25–27% SL. Nape Àattened, nearly square in cross-section. Cephaliclateral-line system on dorsal side of occipitalregion well developed with numerous branchedtubes and pores; skin naked, fragile, damaged inmost specimens (Fig. 4). Snout short, lateral pro¿le nearly an equilateral triangle, its length
almost equal to eye diameter. Eye moderately
large, about one-fourth of HL. Interorbital width

New Glossanodon from Northwestern Paci¿cFig. 4. Cephalic sensory canals and pores on nape ofGlossanodon microcephalus sp. nov., holotype,
NSMT-P 106647, 97 mm SL (stained by cyanine).
Photographed by H. Endo.

slightly less than eye diameter. Mouth moderately small, most of maxillary covered dorso-laterally by lachrymal. Lower jaw projecting
slightly beyond upper, extending posteriorly tovertical line at anterior rim of eye. No teeth on
upper jaws. 10–21 small conical teeth entirely on
lower jaw [left 12, right 14]. 1–2 rows and 1–3
irregular rows of small conical teeth arrayed on
vomer (about 5–30 teeth, generally 10–20) andpalatines (about 15–30 teeth) respectively [5 onvomer and 2 irregular rows of about 25 teeth oneach palatine]. 3–7 (generally 4–5) small caninelike conical teeth present on tip of tongue [4].
Gill rakers elongate, lath-like, closely arranged.
Branchiostegal rays thin, Àat: 1st slender,
reduced, 2nd to 5th expanded; ¿rst two attachedmedially on ceratohyal, others laterally on epihyal (Fig. 5). Anus immediately anterior to anal¿n origin. Pyloric caeca 10–11 (10 in BSKU
104224 and BSKU 104225, and 11 in BSKU
104226, BSKU 104227, BSKU 104228-9, and
BSKU 104228-10).
Scales large, deciduous; lateral-line scales
elongate transversely, posterior margins with a
medial dent; 44–45 lateral-line scales (in 11
specimens; scale pockets were dif¿cult to countin most specimens) [44].
Color when fresh (Fig. 2). Head and bodywhitish and silvery. Lateral head from lachrymal
to opercular region, iris, and a longitudinal bandon side of body bright silver: the band narrow

21

Fig. 5. Hyoid arch of Glossanodon microcephalus sp.
nov., BSKU 104224, 93 mm SL, left lateral(above) and medial (below) views. Bar indicates2 mm.

near each end, widest at the middle of dorsaland anal-¿n origins. Anterior of snout, upper
jaws, and pupil, and dorsal of eye, side of nape,and supracleithrum blackish. A longitudinal broken stripe above lateral line dark, sparsely pigmented: alternately composed of short bars andblotches, rather obscure near head. All ¿n bases
except adipose ¿ns blackish: densely black nearbase of ¿rst two dorsal-¿n rays; a blotch on
upper lobe of caudal-¿n base yellowish; lower
lobe of caudal ¿n near its base with a blackish
triangular blotch.
Color in alcohol (Figs. 2–4, 6). Body light yellow to ocher (all bright silver coloration faded).
Iris darkish with white crescent above whitish
pupil. Anterior snout, anterior rim of lachrymal,
premaxillary, anteroventral of maxillary, anteriormost portion of gular region just behind chindensely pigmented. Anterior of dentary and mandibular rami sparsely pigmented. Posteroventral
corner of orbit (anterior surface of 4th suborbital
within the orbital cavity) densely pigmented.
Buccal cavity partly pigmented on posterior oflower jaw, palatines and ectopterygoids. No
melanophores on gular region except just behindchin, branchiostegal membrane, and ventral sideof body from isthmus to anus. Ventral margins ofinteropercle and subopercle, and posterior rim ofopercle with some melanophores. Dorsal-mostpart of opercle, upper part of supracleithrum,
posttemporal, and supratemporals densely pigmented. Opercle mostly translucent except the22

H. Endo and K. Nashida
Table 2. Proportional measurements and counts of Glossanodon microcephalus and G. pseudolineatus. Asterisk
indicates data from the original description.
G. microcephalus
Holotype
NSMT-P
10664723
Japanese
spec.

Standard length (mm)97
72–96
As % of standard length
Predorsal length
46.4
46.4–48.7
Preanal length
84.3
82.3–85.5
Prepectoral length
25.5
25.2–26.4
Prepelvic length
51.4
49.9–53.9
Postanal length
16.1
14.5–17.7
Postdorsal length
53.7
52.4–55.0
Snout to adipose-¿n origin
87.0
85.8–88.0
Dorsal- to adipose-¿n origins
40.8
39.2–41.5
Pectoral- to pelvic-¿n origins
26.2
24.2–27.8
Pelvic- to anal-¿n origins
33.3
32.6–34.9
Anus to anal-¿n origin
3.1
2.5–3.8
Body depth at pectoral-¿n base
12.2
10.7–14.1
Body width at pectoral-¿n base
10.6
8.9–11.6
Body depth at dorsal-¿n base
13.9
12.9–15.5
Caudal-peduncle depth
6.3
5.7–6.5
Caudal-peduncle length
9.9
8.6–10.3
Length of dorsal-¿n base
7.8
7.8–9.1
Length of anal-¿n base
7.3
7.0–8.5
Head length
26.0
24.6–26.7
As % of head length
Eye diameter
30.6
29.8–31.8
Pupil diameter
15.9
14.4–16.1
Snout length
29.8
29.8–33.2
Interorbital width
23.4
21.5–25.6
Snout to maxillary end
25.4
24.2–26.4
Maxillary depth
11.5
9.7–11.8
Lower jaw length
36.5
36.3–38.7
Meristics
Dorsal-¿n rays
11
11–12
Anal-¿n rays11
10–12
Pectoral-¿n rays18
17–19
Pelvic-¿n rays (left/right)
10/11
10–12
Vertebrae
31＋13＝44 30–31＋13–14＝44–45Gill-rakers on 1st arch
8＋20＝28 8–9＋19–21＝27–30upper part and rim. A longitudinal broken stripe
above lateral line, composed of densely pigmented short bars and blotches, on a continuous
pale stripe ¿nely pigmented: ¿rst two bars andblotches pale. Dorsal midline of body pigmented
internally except behind adipose ¿n. Ventral midline behind anal ¿n moderately to heavily pigmented internally. All ¿n bases pigmented:densely on ¿rst two rays of dorsal, pectoral, pel-G. pseudolineatus

Paratypes

Holotype*

4 smaller
Japanesespec.

2 spec. fromAMS I.
South China
22805-027
Sea

Paratypes*
4 spec.

53–66

75–78

79

72–80

45.1–47.6
81.5–86.0
26.3–27.6
49.9–51.8
17.3–18.5
53.5–55.2
84.4–88.2
38.7–41.2
23.8–25.7
32.0–33.1
2.8–3.5
11.8–12.9
9.2–10.8
12.4–13.6
6.2–6.7
10.0–10.7
8.3–8.6
7.3–8.5
25.6–26.7

46.4–47.3
83.9–84.4
26.3–27.8
52.2–52.5
16.4–16.5
51.5–52.8
85.1–86.4
38.0–39.9
25.1–26.6
31.6–32.3
3.0–3.2
12.1
9.6–9.7
13.3–13.5
6.2–6.3
9.4–9.7
7.7–8.1
6.6–7.0
25.7–27.2

47.8
82.0
26.6
52.2
18.0
53.9
—
39.7
26.3
29.1
2.5
13.5
11.0
16.1
7.0
9.5
9.4
7.5
26.6

47.8–49.0
80.4–81.9
25.9–27.8
49.6–51.4
18.1–18.6
53.1–55.6—
40.4–41.8
25.1–28.8
30.0–31.7
2.6–2.8
12.8–14.0
10.8
14.9–15.6
6.8–7.3
8.8–9.0
8.2–9.0
7.2–7.8
25.9–27.8

29.6–31.4
14.0–15.0
31.4–32.9
24.2–24.4
25.7–27.2
9.8–11.4
37.3–38.6

29.4–30.1
13.5–15.6
32.6–32.7
20.9–21.8
25.9–27.5
10.9–10.9
35.2–36.0

32.9
15.7
32.4
22.9
25.7
12.4
36.7

31.6–33.0
14.2–16.3
29.2–31.9
21.1–21.8
25.5–28.7
11.6–12.8
34.7–36.7

11
10–11
17–19
10–11
31＋13–14＝44–45

11
11
18
11–12
31–32＋14＝45–468＋20＝28

11
10
18
11
30＋13＝43

10
10
18–19
11
30＋13–14＝43–4424–26

24vic, and anal ¿n; internally on adipose ¿n; 2
blackish blotches present externally on upper andlower caudal ¿n base, lower heavily pigmented
internally. Dorsal-¿n membrane unpigmented;
posterior margin of dorsal-¿n rays sparsely pigmented except distal half of middle rays and allof last 3 rays. Pectoral-¿n membrane partly pigmented near base [pigmentation absent on onethird of lower rays]. Dorsal and ventral sides ofNew Glossanodon from Northwestern Paci¿c23

present specimens collected at the ¿sh market
were uncertain (see Remarks).
Etymology. The species name “microcephalus”
is from the Greek micro, small, and cephalon,
head, in reference to the small head in comparison with those of most congeners.
Remarks. The new species conforms to thegenus Glossanodon in having a narrow space
between the maxillary heads, and characteristic
dentition on the vomer, palatines, and tongue(Cohen, 1958: 143). Further, G. microcephalus
belongs to the subgenus Glossanodon in having
the anus located immediately anterior to the anal¿n origin (vs. well-separated from the origin in
Prosoarchus) and 18–25 pectoral-¿n rays (vs.
12–14 in Prosoarchus).
Among species of the subgenus Glossanodon,
G. microcephalus is clearly distinguished fromthe 8 species of the “polli” group in having 44–46
vertebrae [vs. 49–52 (unknown in Glossanodon
polli Cohen, 1958)], 27–30 gill-rakers (vs. 32–40
in 5 species, 30–36 in Glossanodon elongatus
Kobilyansky, 1998), 19–21 gill-rakers on lowerrim (vs. 23 in Glossanodon mildredae Cohen andAtsaides, 1969, 21–24 in Glossanodon struhsakeri Cohen, 1970), fewer counts of pectoral- andpelvic-¿n rays, more teeth on the tongue, aunique interrupted dark stripe on sides of the
body (vs. a continuous stripe), no melanophores
on isthmus to thorax, and other pigmentation(Cohen, 1958, 1970; Cohen and Atsaides, 1969;
Parin and Shcherbachev, 1982; Kobilyansky,
1998; Endo and Nashida, 2010: table 1; Table 1).
Additionally, G. microcephalus is clearly separated from 3 species of the “lineatus” group,
Glossanodon danieli Parin and Shcherbachev,

Fig. 6. Ventral view of head of Glossanodon microcephalus sp. nov., BSKU 104079, 88 mm SL(above) and Glossanodon semifasciatus, BSKU
92324, 94 mm SL (below). Photographed by H.
Endo.

caudal-¿n branched rays moderately to densely
pigmented. A series of melanophores on lateral
midline of body near caudal ¿n, connected posteriorly to pigmented area around caudal ¿n base.
Peritoneum blackish, densely pigmented with silvery layer restricted ventrally anterior to pelvic¿n bases: internal pigmentation on midline fromabdomen to anus visible externally through thinmuscle layer and transparent region immediately
anterior to anus. Stomach unpigmented.
Distribution. Glossanodon microcephalus has
been recorded from muddy and sandy bottoms ofcentral Tosa Bay, off Kochi, in depths of 116–
156 m (R/V Kotaka-maru) and the South China
Sea in depths of 135–137 m (R/V Hakuho-maru)(Fig. 1). Although the Mimaseʼs offshore trawlers
usually ¿sh around 200–300 m (maximum depth
is ca. 420 m) in Tosa Bay, the depth data of theTable 3. Frequency distributions of 6 counts of Glossanodon microcephalus based on type specimens. Paired ¿ns
were counted both sides.
Fin rays

DorsalCountsNo. of specimens

11
27

Anal

12
3

10
5

11
22

Pectoral123

Gill-rakers
CountsNo. of specimens

27
6

28
11

29
6

17
14
Vertebrae

30
2

44
20

45
7

46
1

18
43

Pelvic
19
3

10
6

11
45

12
9

24

H. Endo and K. Nashida

1982, G. lineatus, and Glossanodon pseudolineatus Kobilyansky, 1998 in having 5 branchiostegalrays (vs. 4), 44–46 vertebrae (vs. 55–57 in theformer two, 43–44 in the last), 27–30 gill-rakers(vs. 32–34 in the ¿rst, 24–26 in the last), 3–7
teeth on the tongue (vs. 0 in the ¿rst two, 2–3 inthe last), and a unique interrupted dark stripe onsides of body (vs. a broad continuous band in the¿rst, a continuous stripe with pale blotches in thesecond, and 7–8 large dark spots in the third)(Parin and Shcherbachev, 1982; Kobilyansky,
1998; Endo and Nashida, 2010: table 1; Table 1).
Although this group is well charactered by having 4 branchiostegal rays, Kobilyansky (1998)
noted that G. pseudolineatus differs greatly fromthe other two species in having lower counts ofvertebrae and gill-rakers, teeth on the tongue,
and in pigmentation of the body and organs. In
spite of the clear differences in the branchiostegal number and the markings on the body,
G. pseudolineatus somewhat resembles the new
species in having the lower counts above-mentioned, in dentition on the tongue and lower jaw,
and in most proportions except caudal peduncle
depth and eye diameter (Tables 1, 2). Among thesubgenus Glossanodon, the loss of the ¿rst
reduced branchiostegal ray, resulting in a reduction from 5 to 4, might have occurred separately
in different lineages.
Moreover, G. microcephalus probably belongs
to the “leioglossus” group in having the following combination of characters as mentioned by
Kobilyansky (1998): 5 branchiostegal rays, teethon the tongue, silver peritoneum covered withmelanophores, a dark stripe on the sides of thebody, and no dark spots on the isthmus to thorax
between the pectoral-¿n bases. The new species,
however, is easily distinguished from 2 speciesof this group, G. leioglossus (Valenciennes inCuvier and Valenciennes, 1848) and G. semifasciatus,in having lower counts of dorsal- and pectoral-¿nrays, gill-rakers, vertebrae, and lateral-line
scales, 10–11 pyloric caeca (vs. 15–18 in the latter), a shorter head (HL 25–27% SL vs. 30–32 in
the former, 27–29 in the latter), a shorter snout(its length 7.7–8.4 % SL vs. 9.0–10.3 in the for-

Fig. 7. Gonads of Glossanodon microcephalus sp.
nov., BSKU 104223, non-type, 65 mm SL, male(above) and BSKU 104083, paratype, 72 mm SL,
female (below) in preserved condition. Photographed by H. Endo.

mer, 9.7–11.3 in the latter), a longitudinal interrupted stripe (vs. 7–8 round spots on the dorsal
sides of the body in adults), and an unpigmented
stomach (pigmented in the former) (Matsubara,
1943; Cohen, 1958; Endo and Nashida, 2010:
table 1; Fig. 2, Tables 1, 2). Among Japanese
species, G. microcephalus is somewhat similar toyoung of G. semifasciatus, but is easily distinguished in having a pigmented spot on the anterior tip of the gular just behind the chin (vs.
absent in G. semifasciatus).
The dwarf species, G. pygmaeus, is known tomature around 80 mm SL (Cohen, 1958), but
G. microcephalus apparently matures at a smaller
size: developed gonads were found in a male of
65 mm SL (BSKU 104223) and a female of
72 mm SL (BSKU 104083) (Fig. 7). In addition,ripe gonads in both sexes of G. microcephalus
more than 80 mm SL ¿ll the abdominal cavity,and females around 90 mm SL possess ripe eggsof nearly 1 mm in diameter. In 3 females of 64,
66, and 73 mm SL (BSKU 90672, BSKU 90673,
and BSKU 92321), the ovaries are without eggs
and apparently immature. Hence, G. microcephalus
is also a dwarf species of Glossanodon, maturing
around 70 mm SL, and reaching nearly 100 mm
SL.

New Glossanodon from Northwestern Paci¿c

The cephalic lateral-line system on the dorsalside of the occipital region of G. microcephalus
and G. semifasciatus has numerous branchedtubes and pores (Fig. 4). The sensory system ofGlossanodon species has not been previously
reported, because the skin is delicate and is usually lost when the ¿sh is trawled.
The two known localities of G. microcephalus,
southern Japan and the south of the South China
Sea, suggest that the new species probably
occurs widely on the continental shelf in the
Northwestern Paci¿c from Japan to Southeast
Asia near the equator. Around Japan, the species
is known from Tosa Bay, off Kochi, south of Shikoku Island and from Ainan-cho, Ehime, southwest of Shikoku Island based on a photographwithout voucher specimen (10 cm long, taken in
March of 2008) (Takagi et al., 2010). In Tosa
Bay, the new species was not recorded prior to2007, but 30 (46–92 mm SL) and 15 (80–97 mm
SL, including the holotype) specimens were collected at depths of about 120 m by two tows of
the R/V Kotaka-maru on 3 March and 6 July of2010 respectively. Further, 36 specimens (65–
95 mm SL) were collected at Mimase ¿sh market
on 19 March of 2010. Most of these were mature
adults. During biological research of G. semifasciatus in Tosa Bay (via sampling at the Mimase¿sh market), Nashida et al. (2007) reported ¿shing depths of about 160–360 m (usually 200–250m) by offshore trawlers from October to April in2001 to 2007. Considering the depth records(116–156 m) of G. microcephalus by two research
vessels and the ¿shing depths of G. semifasciatus
in Nashida et al. (2007), G. microcephalus isapparently an inhabitant of the continental shelfin depths of about 100–200 m. On the other hand,no adults of G. lineatus, G. kotakamaru, and G.
semifasciatus have been collected by R/V
Kotaka-maru in depths of 100–200 m in Tosa
Bay (Kitagawa and Okiyama, 1997; Nashida etal., 2007; Endo and Nashida, 2010).
Comparative materials. Glossanodon semifasciatus (7 specimens): Tosa Bay, off Kochi, BSKU
53400 (166 mm SL), BSKU 78403 (142), BSKU
92322 (104), BSKU 92324 (94); Suruga Bay, off

25

Shizuoka, NSMT-P 50053 (133), NSMT-P 11187(168); Wakasa Bay, off Kyoto, Japan Sea,
NSMT-P 79780 (142). Glossanodon australis(2), Glossanodon kotakamaru (15), and Glossanodon lineatus (5) in Endo and Nashida (2010).
Acknowledgments
We are most grateful to Drs. Keiichi Matsuura(NSMT) and Seishi Kimura (Fisheries ResearchLaboratory, Mie University) for their efforts in
preparing this supplement. Dr. Hideo Sakaji(Fisheries Research Agency, Japan), the crews of
R/V Kotaka-maru (NRIFS) and the offshore
trawler Kousei-maru, the Mimase Fishing Cooperation (Kochi City), and Mr. Naohide
Nakayama, Shun-suke Yamamoto and Kenta
Kenmotsu (BSKU) assisted in collecting andobtaining specimens. We also thank Dr. Eri Katayama for taking the radiographs and constructing
the map, Mr. Naohide Nakayama for taking thephotographs, and Mr. Mark McGrouther and Ms.
Amanda Hay (AMS), Dr. Yoshiaki Kai (FAKU),
and Dr. Gento Shinohara (NSMT) for loaning
and cataloging the type specimens. We also thank
Mr. Gordon Yearsley (Hobart, Australia) for editing the English text. The study was partly supported by the grant-in-aid of “Marine Science
project” of Natural Science Cluster, Sciences
Unit, Kochi Univerisity.

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26

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Associate editor: K. Matsuura