Bull. Natl. Mus. Nat. Sci., Ser. A, 49(4), pp. 179–189, November 22, 2023
DOI: 10.50826/bnmnszool.49.4_179

A Rare Flatﬁsh, Samaris spinea (Teleostei: Pleuronectiformes:
Samaridae) from the Ogasawara Islands, Japan,
with Notes on Its Distribution, Taxonomy and Sexual Dimorphism
Kota Obata1, *, Toshio Kawai1 and Gento Shinohara2, 3
1Faculty/Graduate School of Fisheries Sciences, Hokkaido University,
3–1–1 Minato-cho, Hakodate, Hokkaido 041–8611, Japan2
Department of Zoology, National Museum of Nature and Science,
4–1–1 Amakubo, Tsukuba, Ibaraki 305–0005, Japan
3
The Hokkaido University Museum,
Kita 10-jo Nishi 8-chome, Kita-ku, Sapporo, Hokkaido 060–0841, Japan*E-mail: obata.kota.z1@elms.hokudai.ac.jp(Received 7 July 2023; accepted 20 September 2023)

Abstract A single specimen of the samarid ﬂatﬁsh, Samaris spinea Mihara and Amaoka, 2004,
was collected oﬀ the northwest coast of Ototo-jima Island, Ogasawara Islands, Japan. This specimen represents the third occurrence of this species and the second record from Japan and theNorthern Hemisphere. We report morphological characters of the specimen in detail with discussion of small spines along the dorsal and ventral margins of the caudal peduncle and the intermuscular bones. We conﬁrmed the small spines coming out from large, plate-like scale. It is also
revealed that distributional patterns of intermuscular bones of S. spinea are diﬀerent from those of
the congeneric species, S. cristatus: epimerals are absent and hypomerals are present only on
abdominal and anterior caudal vertebrae in S. spinea. Although the present specimen bears a testis,
male character as prolonged anterior dorsal- and pelvic-ﬁn rays on ocular side is not appeared.
This may be related to the presence of a single isopod parasite in the gill. The taxonomic confusion
on gender of the generic name is also ﬁxed.
Key words: Bonin Islands, CT, ctenoid scales, intermuscular bones, parasitic infection.

Introduction
The Spined Cockatoo Righteye Flounder,
Samaris spinea Mihara and Amaoka, 2004,
belonging to the family Samaridae (Pleuronectiformes), is characterized by the presence of small
spines along the dorsal and ventral margins of
the caudal peduncle (Amaoka et al., 2004;
Mihara and Amaoka, 2004). The species has
been recorded only from New Caledonia (typelocality) and the East China Sea oﬀ the Kerama
Islands, Okinawa, Japan (Amaoka et al., 2004;
Mihara and Amaoka, 2004).
In 2009, a single specimen of S. spinea was© 2023 National Museum of Nature and Sciencecollected with an ORI biological dredge (Namikawa et al., 2011: ﬁg. 2A) oﬀ the northwest coastof Ototo-jima Island, Ogasawara Islands (Bonin
Islands), Japan (Fig. 1). This specimen represents
the third example of the species, and the second
record from Japan. The specimen indicates arange extension of S. spinea eastward by
1,400 km in the northern hemisphere. Because nosamarid species have been reported from theOgasawara Islands (see Randall et al., 1997;
Nakabo and Doiuchi, 2013; Amaoka, 2016), it
represents the ﬁrst record of the family Samaridae from the Islands. We describe its morphology
and discuss on the small spines along the dorsal
and ventral margins of the caudal peduncle andits intermuscular bones with computed tomogra-

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phy (CT) scanning which enables to examineinternal morphology of rare specimens without
dissection. A biological note on the sexual dimorphism is also provided.

Kyoto) (0.028 mm/voxel, 100 kv) and threedimensional reconstruction images produced by
the rendering software VGSTUDIO MAX ver.
3.3 (Volume Graphics, Nagoya).

Material and Methods

ResultThe specimen reported is deposited in the
Department of Zoology, National Museum of
Nature and Science, Tsukuba (NSMT); comparative specimens are lodged in the Laboratory ofMarine Biology, Faculty of Science, Kochi University, Kochi (BSKU), the Hokkaido University
Museum, Hakodate (HUMZ) and the Muséum
national dʼHistoire naturelle, Paris (MNHN).
Counts and proportional measurements mainly
follow Hubbs and Lagler (1958). All dorsal- andanal-ﬁn rays are counted as individual rays. Snout
length is measured from the anterior margin oflower orbit to the tip of upper jaw. Lengths of thelongest anterior prolonged dorsal-ﬁn ray and the
middle caudal-ﬁn ray are measured from the baseto the distal tip of the respective rays. The standard
length and head length are abbreviated as SL and
HL, respectively. Vertebral counts were determined from radiographs and are expressed asabdominal ＋ caudal vertebrae. All measurements
were made to the nearest 0.1 mm with digital calipers and divider. The terminology of sensory poreson the head follows Voronina (2009). Although
Patterson and Johnson (1995) has since redeﬁned
intermuscular bones of teleostean ﬁshes, our terminology follows Sakamoto (1984) and Hensley and
Ahlstrom (1984) for comparison with the many
previous studies on the systematics of ﬂatﬁshesthat used their deﬁnition. Two intermuscular bones(epicentra and epimerals) and the hypomerals ofSamaris correspond with neoneurals and ribs ofPatterson and Johnson (1995), respectively.
A map of collection sites of S. spinea (Fig. 1)
showing bathymetric imagery was made with
GMT 5.4.5 using data from ETOPO1 (Amanteand Eakins, 2009).
Spines and osteological characters of NSMT-P
109872 were investigated with CT scanning using
inspeXio SMX-225CR FPD HR Plus (Shimadzu,

Order Pleuronectiformes
Family Samaridae
Genus Samaris Gray, 1831
Samaris spinea Mihara and Amaoka, 2004
[Standard Japanese name: Toge-hatatate-garei](Figs. 2–4; Table 1)

Samaris spinea Mihara and Amaoka, 2004: 624, ﬁgs.
8–13, 20; Amaoka et al., 2004: 2, ﬁgs. 1–3; Fricke andKulbicki, 2006: 355; Voronina and Suzumoto, 2017: 7,
ﬁg. 6; Voronina and Volkova, 2019: 274, ﬁg. 24.
Samaris spineus: Nakabo and Doiuchi, 2013: 1685; Nakabo
and Hirashima, 2015: 266; Amaoka, 2016: 203, ﬁg. 6.

Specimen examined. NSMT-P 109872, 32.9 mm
SL, male, oﬀ northwest coast of Ototo-jimaIsland, Ogasawara Islands, Tokyo Prefecture,
Japan, 27°13′05″N 142°09′11″E to 27°13′11″N142°09′13″E, 135.8–135.5 m depth, 15 July 2009,
50 cm ORI dredge, R/V Koyo-maru.
Diagnosis. Samaris spinea is separable fromthe other species of Samaris by the following
combination of characters: dorsal-ﬁn rays 60–72;
prolonged dorsal-ﬁn rays 3–7; anal-ﬁn rays
46–54; lateral line scales 44–58; vertebrae 9–10
＋27–31; body depth 36.0–41.5% SL; caudal-ﬁnrays bifurcated except uppermost and lowermost
two simple rays; 2–6 spines along dorsal andventral margins of caudal peduncle on ocularside (Amaoka et al., 2004; Mihara and Amaoka,
2004; present study).
Description. Proportional measurements (%SL) and counts are provided in Table 1.
Head length 4.0 in SL on ocular side, 3.8 onblind side; body depth 2.6 in SL; snout length 4.0
in HL; upper eye diameter 3.2 in HL; lower eye
diameter 3.0 in HL; interorbital width 23.6 in
HL; upper jaw length 3.0 in HL on ocular side,
3.6 on blind side; lower jaw length 1.9 in HL on
ocular side, 2.2 on blind side; caudal peduncle
length 17.0 in SL; caudal peduncle depth 8.3 inSamaris spinea from Ogasawara Islands

181

Fig. 1. Map showing collection localities for specimens of Samaris spinea reported. Star, diamond and triangles:
records for the present specimen, and those in Amaoka et al. (2004) and Mihara and Amaoka (2004), respectively.

SL; pectoral-ﬁn length 3.5 in SL on ocular side;
pelvic-ﬁn length 4.8 in SL on ocular side, 7.1 onblind side; pelvic-base length 13.2 in SL on ocular side, 20.2 on blind side; middle caudal-ﬁn ray
length 3.5 in SL; length of anterior prolonged
dorsal-ﬁn ray 4.0 in SL.
Body laterally compressed, elliptical, deepest at
midpoint (Fig. 2). Head small, the dorsal proﬁleslightly sloping anteriorly; head on ocular sideslightly smaller than that on blind side. Eyes dextral, of moderate size, separated by scaleless narrowbony ridge; both eyes naked except for lower partof upper eye with one weak ctenoid scale; anterior
margins of upper and lower eyes nearly on samevertical line. Nostrils on ocular side two, situatedanterior to interorbital space; both nostrils on ocularside with long nasal tube, anterior tips reaching
upper jaw when bent antero-ventrally; nostrils
absent on blind side. Pores of supraorbital canal on
ocular side two; pores of supraorbital canal on blindside absent. Mouth oblique; anterior tip of premaxilla just in front of upper margin of lower orbit;
maxilla extending below anterior margin of lower
eye, not reaching below middle of lower eye; lower

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K. Obata et al.
Table 1. Proportional measurements and counts of Samaris spinea.
Present study

Amaoka et al. (2004)

NSMT-P 109872
Male

BSKU 57843
Male

Holotype
Male

Mihara and Amaoka (2004)
Paratypes (n ＝ 28)
Males and females

SL (mm)Measurements (% SL)
HL on ocular side
HL on blind side
Body depth
Snout length
Upper eye diameter
Lower eye diameter
Interorbital width
Upper jaw length on ocular side
Upper jaw length on blind side
Lower jaw length on ocular side
Lower jaw length on blind side
Caudal peduncle length
Caudal peduncle depth
Pectoral-ﬁn length
Pelvic-ﬁn length on ocular side

32.9

38.8

49.1

21.0–53.2

25.1
26.7
39.0
6.3
7.9
8.4
1.1
8.3
7.4
13.4
12.2
5.9
12.1
28.5
20.8

25.3
25.1*
38.4
6.4
9.3
8.5
1.8
9.0
7.2
14.9
12.9
7.2*
10.3
31.2
42.8

23.4
—
37.2
5.9
6.7
7.1
1.2
7.5
6.7
11.0
10.2
—
12.8
24.4
47.5

Pelvic-ﬁn length on blind side
Pelvic-base length on ocular side
Pelvic-base length on blind side
Length of the longest anterior
prolonged dorsal-ﬁn ray
Length of middle caudal-ﬁn ray
Counts
Dorsal-ﬁn rays
Anal-ﬁn rays
Caudal-ﬁn rays
Pectoral-ﬁn rays
Pelvic-ﬁn rays on ocular side
Pelvic-ﬁn rays on blind side
Lateral line scales
Vertebrae
Spines on caudal peduncle
along dorsal margin
along ventral margin

14.1
5.9
5.0
24.8

10.3
6.4
5.4
63.1

11.7
5.1
3.9
54.0

28.6

38.7

33.4

21.3–28.4
22.1–28.7 (n ＝ 6) *36.0–41.5
5.0–6.8
6.2–9.7
6.4–9.7
0.6–1.9
6.9–9.9
6.0–8.6
10.4–14.4
9.3–13.1
6.3–8.5 (n ＝ 6) *11.2–13.5
24.3–31.9
14.9–60.0 (males)
11.4–20.5 (females)
9.0–12.6
4.2–5.7
3.3–4.4
10.4–68.2 (males)
8.6–31.2 (females)
26.6–41.9

68
50
16
4
5
5
ca. 57
10 ＋ 31

68
51
16
4
5
5
ca. 58*
10 ＋ 28

62
50
16
4
5
5
53
10 ＋ 27

60–72
46–54
15–16
4
5
5
44–58
9–10 ＋ 27–30

5
6

4*
4*

4*
4*

2–5 (n ＝ 26) *3–5 (n ＝ 26) **Data obtained by present study

jaw slightly protruded; teeth small, in bands on bothjaws. Vomer and palatine toothless. Gill rakers onﬁrst arch rudimentary on both limbs, but moredeveloped on lower limb. Gill membranes united toeach other. Scales ctenoid on head and body on
ocular side, cycloid on head on blind side, cycloid
and weakly ctenoid on anterior 1/3 part of body on
blind side, weakly ctenoid on posterior 2/3 part ofbody on blind side; strongly ctenoid on dorsal-,anal-, caudal- and pelvic-ﬁn bases of both sides;
scales absent on snout, interorbital region, mostparts of eyes, upper jaw, and dorsal, anal, pectoraland pelvic ﬁns, and posterior 2/3 of caudal ﬁn. Lat-eral line on ocular side nearly straight; lateral line
absent on blind side.
Small spines present along dorsal and ventral
margins of caudal peduncle; ﬁve on dorsal margin with fourth longest and ﬁfth shortest, ﬁrst,
second and fourth simple, third and ﬁfth bifurcated; six on ventral margin with ﬁfth longest
and ﬁrst shortest, ﬁrst, second, third and ﬁfth
simple, fourth and sixth bifurcated (Figs. 3, 4).
Dorsal-ﬁn origin anterior to upper orbit; dorsal-ﬁn membrane originating just behind anterior
part of upper jaw on blind side; ﬁrst three dorsalﬁn rays prolonged, with ﬁrst and second rays lon-

Samaris spinea from Ogasawara Islands

183

Fig. 2. Lateral view of ocular (A) and blind (B) sides of Samaris spinea, NSMT-P 109872, 32.9 mm SL, Ogasawara Islands, Japan.

ger than third. Anal-ﬁn origin slightly posterior toanus. Pectoral-ﬁn rays on ocular side short, notreaching middle of body; pectoral ﬁn absent on
blind side. Pelvic-ﬁn rays on ocular side prolonged, third ray greatly prolonged, ﬁrst and second rays broken; pelvic-ﬁn rays on blind side
short; pelvic-ﬁn base on ocular side longer thanbase on blind side; pelvic-ﬁn origin on ocularside slightly ahead of origin on blind side. All
dorsal-, anal-, pectoral- and pelvic-ﬁn rays simple. Caudal ﬁn elongated and rounded; all caudalﬁn rays bifurcated except uppermost and lower-

most two simple rays; middle rays longest. Anuson midventral line between pelvic and anal ﬁns.
Urogenital papilla positioned on ocular side adjacent to anus.
Epicentra present on lateral sides of second tosixth abdominal vertebrae; absent on caudal vertebrae (Figs. 3, 5). Epimerals absent. Hypomerals
present on ventral sides of fourth abdominal vertebrae to fourth (ocular side) or sixth (blind side) caudal vertebrae; absent on posterior caudal vertebrae.
Color in alcohol (Fig. 2). Ocular side of bodywhitish brown; two brown blotches just below lat-184

K. Obata et al.

Fig. 3. CT images of osteology on ocular (A) and blind (B) sides of Samaris spinea, NSMT-P 109872, 32.9 mm SL.

eral line behind pectoral ﬁn; three to four small
brown blotches on dorsal and ventral margins ofbody; large brown blotch on posterior-most partsof dorsal- and anal-ﬁn bases. Blind side of bodywhitish brown without spots or dots. Dorsal- andanal-ﬁn membranes with ﬁve brown blotches andmany small brown dots basally. Caudal ﬁn withbrown blotch basally, large brown blotch centrally,and small brown dots distally. Pectoral-ﬁn membrane uniformly brown; pelvic-ﬁn membrane uniformly whitish and transparent.
Distribution. Known from New Caledonia,
and Ryukyu Islands (oﬀ Kerama Islands) andOgasawara Islands, Japan at depths of
44–135.5 m (Amaoka et al., 2004; Mihara andAmaoka, 2004; present study; Fig. 1).

Discussion
The genus Samaris Gray, 1831 comprises ﬁvevalid species: Samaris cristatus Gray, 1831,
Samaris macrolepis Norman, 1927, Samaris costae Quéro, Hensley and Maugé, 1989, Samaris
chesterﬁeldensis Mihara and Amaoka, 2004 andSamaris spinea Mihara and Amaoka, 2004. The
last two species are easily separable from theother three in having bifurcated middle caudalﬁn rays and spines along dorsal and ventral margins of caudal peduncle (Amaoka et al., 2004;
Mihara and Amaoka, 2004). Samaris spinea andS. chesterﬁeldensis are separable from each otherby body depth (36.0–41.5% SL vs. 31.2–35.5%
SL, respectively: Amaoka et al., 2004; Mihara
and Amaoka, 2004). Characters of the present

Samaris spinea from Ogasawara Islands

185

Fig. 4. CT images of transformed scales with small spines along dorsal (A) and ventral (B) margins of caudal
peduncle on ocular side of Samaris spinea, NSMT-P 109872, 32.9 mm SL.

specimen are consistent with those in the originaldescription of S. spinea provided by Mihara andAmaoka (2004) and the description provided by
Amaoka et al. (2004) (Table 1). The number of
caudal vertebrae (31) and spines on caudal
peduncle (5–6) of the present specimen diﬀerslightly from those of the previous studies (27–30 and 2–5 in Amaoka et al., 2004; Mihara andAmaoka, 2004) (Table 1). These diﬀerences are
considered to be intraspeciﬁc variation.

Small spines along dorsal and ventral margins of
the caudal peduncle protrude from large, plate-likescales. The proximal half of the spine is embeddedin the skin adjacent the proximal pterygiophores ofthe dorsal and anal ﬁns (Figs. 3, 4; also see Amaoka
et al., 2004: ﬁg. 3; Voronina and Volkova, 2019: ﬁg.
24B). The distal half of the spine is continuousfrom the proximal half, acute, extends posteriorly,
and is exposed external to the body surface. The
distal half of the spines also varies in shape, i.e.,

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K. Obata et al.

simple, bifurcate or trifurcate. Among the 29 specimens of S. spinea for this study, the Ogasawara
Islands specimen and two other specimens (HUMZ
172359 and MNHN 2000-0729) have simple andbifurcated spines (Fig. 4), another ﬁve specimens(HUMZ 172357, MNHN 2000-0710, 2000-0711,
2000-0712 and 2000-0730) have simple and trifurcated spines, and the rest of the specimens have
only simple spines. The variation found in the
shape of spines does not appear to be related to thesize, sex or collection locality of the specimens.
Among ﬂatﬁshes, it is well known that scales
are uniquely modiﬁed as bony plates or tubercles
in two species of pleuronectid, Clidoderma asperrimum (Temminck and Schlegel, 1846) andPlatichthys bicoloratus (Basilewsky, 1855), and a
species of scophthalmid Scophthalmus maximus(Linnaeus, 1758) (Sakamoto, 1984; Zylberberg etal., 2003; Abe et al., 2013; Märss et al., 2015).
The morphology of the modiﬁed scales with small
spines on the caudal peduncle of S. spinea resemble the modiﬁed ctenoid scales in the pleuronectid

Platichthys ﬂesus (Linnaeus, 1758) (Märss et al.,2015: ﬁg. 6D–H, J, K). The small spines on thecaudal peduncle in S. spinea may also have originated from ctenoid body scales.
Intermuscular bones of Samaris have only been
investigated in S. cristatus, which has three series
of intermuscular bones, i.e., epicentra, epimerals
and hypomerals (Hensley and Ahlstrom, 1984;
Sakamoto, 1984). We found the Ogasawara
Islands specimen to have epicentra and hypomerals, but not epimerals. Additionally, although the
epimerals and hypomerals of S. cristatus are distributed from abdominal vertebrae to posteriorcaudal vertebrae (Hensley and Ahlstrom, 1984;
Sakamoto, 1984), the hypomerals of our specimen
are present only on abdominal vertebrae and anterior caudal vertebrae (Fig. 5). Judging from X-ray
images in previous studies (Amaoka et al., 2004:
ﬁg. 3; Voronina and Volkova, 2019: ﬁg. 24B),
other specimens of S. spinea lack epimerals andhave the same distribution of hypomerals. Therefore, the presence or absence of epimerals, andFig. 5. CT images of osteology of head and anterior body on ocular side in Samaris spinea, NSMT-P 109872,
32.9 mm SL. EC: epicentrum; HM: hypomeral.

Samaris spinea from Ogasawara Islands

distribution of hypomerals vary among species ofSamaris.
Samaris spinea is known to be sexually dimorphic, with extremely prolonged anterior dorsal-ﬁnrays and pelvic-ﬁn rays on the ocular side of males(Amaoka et al., 2004: ﬁg. 1; Mihara and Amaoka,
2004: ﬁgs. 12, 13). The Ogasawara Islands specimen is a male with a reduced testis on the ocularside only. Both its prolonged anterior dorsal-ﬁnrays and pelvic-ﬁn rays (ocular side) are shorter
than those of other males (24.8% SL and 20.8% SL
in the present specimen vs. more than 40% SL and
40% SL in males over 33.5 mm SL; Mihara andAmaoka, 2004: ﬁgs. 12, 13). A large parasitic isopod was found on the gills of the blind side of our
specimen (Fig. 6). This isopod is a species of thefamily Cymothoidae, which are known to be parasitic widely on ﬁshes, including the pleuronectiforms (e.g., Kumar and Bruce, 1997; Trilles andJustine, 2006) (Ryota Kawanishi, personal communication). Some species of the Cymothoidae
have been reported to cause parasitic castration in
their hosts (e.g., Lima et al., 2007; Fogelman et al.,2009; Laﬀerty and Kuris, 2009; Silva et al., 2021).
Parasitic castration may have occurred in the present specimen.
Gray (1831) originally described the genus
Samaris, for Samaris cristatus. Because the speciﬁc name cristatus is masculine, Gray (1831)
regarded Samaris as being masculine as well.
Nakabo and Doiuchi (2013) disagreed and followed Gray, using Samaris spineus for Mihara
and Amaokaʼs Samaris spinea. They missed thepoint that the ICZN (1999: Art. 30.1.1) rulingthat “if it (＝ a generic name) is a compound
word formed from two or more components, thegender is given by the ﬁnal component.” AsSamaris is a combination of the two Latin words,
Samara (noun; masculine) and -is (suﬃx; feminine) (Nakabo and Hirashima, 2015), we consider the gender of Samaris to be feminine aswell and follow the ICZN ruling, using Samarisspinea as the speciesʼ scientiﬁc name.
Comparative specimens
Holotype: MNHN 2000-0724, 49.1 mm SL,

187

male, New Caledonia, 20°27.35′S 161°4.70′E,
75–74 m depth, 22 July 1988.
Paratypes: HUMZ 172354, 34.5 mm SL, female,
New Caledonia, 20°36.14′S 161°1.75′E, 86 m
depth, 22 July 1988; HUMZ 172355, 40.5 mm
SL, male, HUMZ 172356, 46.4 mm SL, male,
MNHN 2000-0718, 42.1 mm SL, male, MNHN
2000-0719, 39.7 mm SL, male, MNHN 20000720, 33.5 mm SL, male, New Caledonia,
20°40.8′S 158°51.5′E, 77 m depth, 21 Aug. 1988;
HUMZ 172357, 48.4 mm SL, male, HUMZ
172358, 22.5 mm SL, male, HUMZ 172359,
21.3 mm SL, female, MNHN 2000-0727,
21.9 mm SL, male, New Caledonia, 22°48.3′S166°59.6′E, 53 m depth, 17 July 1985; MNHN
2000-0708, 29.0 mm SL, male, New Caledonia,
21°18.00′S 158°50.07′E, 66 m depth, 19 Oct.
1985; MNHN 2000-0709, 46.6 mm SL, male,
New Caledonia, 20°31.50′S 161°6.45′E, 88 m
depth, 15 July 1984; MNHN 2000-0710,
34.8 mm SL, male, MNHN 2000-0711, 32.1 mm
SL, female, New Caledonia, 20°34.30′S
158°47.4′E, 67 m depth, 23 July 1984; MNHN
2000-0712, 42.9 mm SL, male, MNHN 20000713, 35.9 mm SL, male, New Caledonia,
21°24.90′S 159°9.30′E, 60 m depth, 25 July
1984; MNHN 2000-0714, 45.6 mm SL, male,
New Caledonia, 20°30′S 160°57′E, 81 m depth,
31 Aug. 1988; MNHN 2000-0715, 51.9 mm SL,
male, New Caledonia, 21°19′S 158°48′E, 66 m
depth, 19 Oct. 1985; MNHN 2000-0721,
43.5 mm SL, male, MNHN 2000-0722, 34.3 mm
SL, male, New Caledonia, 20°21.29′S
160°58.60′E, 75–74 m depth, 22 July 1988;
MNHN 2000-0723, 47.5 mm SL, male, New
Caledonia, 20°27.35′S 161°4.70′E, 75–74 m
depth, 22 July 1988; MNHN 2000-0725,
31.1 mm SL, female, New Caledonia, 20°36.14′S
161°1.75′E, 86 m depth, 22 July 1988; MNHN
2000-0726, 52.4 mm SL, male, New Caledonia,
21°19.0′S 158°52.3′E, 64 m depth, 19 Oct. 1985;
MNHN 2000-0728, 44.9 mm SL, male, New
Caledonia, 22°25.00′S 166°59.60′E, 47 m depth,
23 Oct. 1984; MNHN 2000-0729, 27.9 mm SL,
female, MNHN 2000-0730, 22.0 mm SL, male,
New Caledonia, 22°48.30′S 166°59.60′E, 53 m

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K. Obata et al.

Fig. 6. Lateral view of head on blind side of Samaris spinea, NSMT-P 109872, 32.9 mm SL, showing a positionof underlying parasitic isopod on the gill. Arrow head indicates cephalon.

depth, 17 July 1985.
Nontype: BSKU 57843, 38.5 mm SL, male, East
China Sea oﬀ Kerama Islands, Okinawa, Japan,
26°15.4′N 127°15.9′E to 26°15.4′N 127°16.1′E,
95–101 m depth, 19 Apr. 2002.
Acknowledgements
We deeply thank Martin F. Gomon (Museums
Victoria, Melbourne) for critically reading a draft
manuscript. We are grateful to Hiroshi Namikawa and Hironori Komatsu (NSMT) and Captain Ichiro Gonoi and all crews of the R/V Koyomaru (Tokyo Metropolitan Ogasawara Fisheries
Center) for providing the present specimen.
Ryota Kawanishi (Hokkaido University of Education) kindly helped identiﬁcation of the parasite isopod and provided valuable information.
We express gratitude to Hiromitsu Endo
(BSKU), Fumihito Tashiro (HUMZ), and Patrice
Pruvost, Zora Gabsi and Jonathan Pﬂiger(MNHN) for helping examination of comparative specimens. Kunio Amaoka and Hisashi
Imamura (HUMZ) advised on an early draft

manuscript. Our thanks go to Shuhei Nomura,
Takahiko Kutsuna and Yasunari Shigeta (NSMT)
for their maintenance and valuable support on
the micro-CT scanner and software in the
Research Wing, Tsukuba District. This study waspartially supported by JST SPRING Grant Number JPMJSP2119 and JSPS KAKENHI Grant
Number JP23K05364.
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