Bull. Natl. Mus. Nat. Sci., Ser. A, 35(2), pp. 125–136, June 22, 2009

Rare Crabs (Crustacea, Decapoda, Brachyura) from Okinawa Island,with Description of a New Species of the Family Leucosiidae
Hironori Komatsu1 and Masatsune Takeda2
1

Department of Zoology, National Museum of Nature and Science,
3–23–1 Hyakunincho, Shinjuku-ku, Tokyo, 169–0073 Japan
E-mail: h-komatu@kahaku.go.jp
2
Faculty of Modern Life, Teikyo Heisei University,
2–51–4 Higashi-Ikebukuro, Toshima-ku, Tokyo, 170–8445 Japan
E-mail: takeda-m@thu.ac.jp

Abstract A small collection of brachyuran crabs made by night SCUBA at Okinawa Island, theRyukyu Islands, is examined. A new species of leucosiid crab, Heteronucia fujitai, is describedand illustrated based on single female specimen. Heteronucia fujitai is similar to H. laminata, but
can be distinguished from H. laminata by the broader carapace, the fourth ambulatory leg being
without laminar margin, and the concealed first segment of the female abdomen. All the species
examined are listed, and some rare species of the families Aethridae, Leucosiidae, and Parthenopidae are noted with supplementary descriptions and remarks.
Key words : Crustacea, Decapoda, Brachyura, Okinawa, Ryukyu Islands, Heteronucia fujitai, newspecies.

Introduction

Taxonomy

Okinawa Island in the Ryukyu Islands is located in the southwestern most part of Japan. It isstrongly influenced by the main stream of thewarm Kuroshio Current and is known to havevery rich fauna. Numerous surveys had alreadybeen carried out around this island, however, thefauna still remains to be completely elucidated.
A small collection of brachyuran crabs madeby night SCUBA at the littoral area of Okinawa
Island was provided us by Dr. Yoshihisa Fujita of
the University of the Ryukyus. Since most of
crabs inhabiting shallow water are more active in
the night than in the daytime, night SCUBA is a
useful method for collecting shallow-water crabs.
Measurements, given in millimeters (mm), areof the greatest carapace length (cl) (including theposterior lobe and excluding the rostral spine)and breadth (cb), respectively. All the specimens
examined are deposited in the National Museumof Nature and Science (NSMT).

Family Dromiidae
Lewindromia unidentata (Rüppell, 1830)[Japanese name: Kinuge-kamuri](Fig. 1A)

Material examined. Cape Maeda, Onna, Okinawa I., 7.8 m deep; 1? (cl 21.4cb 19.7),
NSMT-Cr 20822; 16 August 1998.
Distribution. Widely distributed in Indo-Pacific (McLay, 1993).
Family Homolidae
Latreillopsis laciniata Sakai, 1936
[Japanese name: Edatoge-mizuhiki-gani](Fig. 1B)

Material examined. Cape Maeda, Onna, Okinawa I., 12.7 m deep; 1/ (cl 11.6 in medianlinecb 8.3 between branchial regions of bothsides), NSMT-Cr 20823; 5 May 1998.
Distribution. Known only from Japan (Guinot

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Hironori Komatsu and Masatsune Takeda

and Richer de Forges, 1995).
Family Calappidae
Calappa gallus (Herbst, 1803)[Japanese name: Kobu-karappa](Fig. 1C)

Material examined. Cape Maeda, Onna, Okinawa I., 8 m deep; 1/ (cl 19.4cb 24.1), NSMTCr 20824; 14 May 1998.
Distribution. Widely distributed in Indo-West
Pacific (Galil, 1997).
Family Leucosiidae
Heteronucia fujitai sp. nov.
[New Japanese name: Manju-ibo-tsubu-kobushi](Figs. 1D, 2–3, 4A–B)
Nucia sp.: Minemizu, 2000, p. 201 (color photograph).

Material examined. Mizugama, Kadena, Okinawa I., 6 m deep; 1 ovig./ (cl 11.5cb 12.9),
holotype, NSMT-Cr 20825; 7 Aug. 1998.
Description of holotype. Carapace (Fig. 1D,4A) subglobular, 1.1 times broader than long;
dorsal surface evenly covered with small rounded
granules, sparsely studded with small, subconicaltubercles and very short, plumose setae; regions
ill-defined, with very shallow, H-shaped groove
between cardiac and intestinal regions. Frontal
region weakly produced, concave medially.
Pterygostomian margin weakly convex outwards.
Branchial margin roundly convex, with 2 small,
triangular tubercles on posterior half, tubercles
weakly hooked and covered with cluster of granules. Posterior margin with 2 small, triangular tubercles on both sides, tubercles covered withcluster of granules.
Ocular peduncle (Fig. 2A) very short. Orbit
with 2 short, straight fissures on dorsal roof, with
V-shaped notch on infraorbital margin; orbital
hiatus open. Antennule obliquely folded into
fossa; basal segment occupying ventral 0.4 offossa, covered with very short setae. Antenna:basal segment transversely ovate; second segment subsquamate, constricted anteriorly. Affer-ent channel without tooth on mesial margin; anterior margin with V-shaped notch on lateral corner.
Mandible (Fig. 3A–B) well calcified; cuttingedge triangular in outline, pointed medially; endopod palp 3-segmented, first segment very
short, densely fringed with stout setae on terminal segment. Maxillule (Fig. 3C): coxal endite
rod-like, directed mesially, fringed with shortsetae, terminal setae stout; basial endite triangular, fringed with stout and thin setae on mesial
margin, with 1 plumose seta on lateral margin;endopod stilliform, with some plumose setae on
proximal part of lateral margin. Maxilla (Fig.
3D): coxal endite roundly bilobed; basial endite
elongate triangular, with some terminal setae; endopod tongue-shaped, with 1 seta on apex; exopod (scaphognathite) longitudinally expanded
into oval structure, entirely fringed with short,plumose setae. First maxilliped (Fig. 3E): coxal
endite rounded, with dense, weakly plumose
setae; basial endite subtriangular, densely fringed
with moderately long, plumose setae alongmesial margin; endopod longitudinally expanded,rounded at apex, fitting in efferent channel,
fringed with very short setae on apex; exopod
longitudinally filiform, with some plumose setae
on apex, bearing flagellum with some terminal
setae. Second maxilliped (Fig. 3F): ischium andmerus fringed with long plumose setae alongmesial margin; propodus with dense setae along
lateral margin and on disto-lateral part; dactylus
armed with stout setae around tip; exopod tapering distally, with some plumose setae on apex,
bearing flagellum with some terminal setae; exodite rounded.
Third maxilliped (Fig. 3G–H) covered withround granules of various sizes; basis fused withischium but with suture on both surfaces; ischium subsquamate; merus moderately bent dorsallyin situ, about 0.76 times as long as ischium alongmesial margin; propodus and dactylus with distally denticulate, stout setae along inner margin;
exopod subsquamate, rounded at tip, fringed withshort plumose setae along lateral margin; internal
exopodal ridge prominent, with dense setae along

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127

Fig. 1. A, Lewindromia unidentata (Rüppell, 1830), male (cl 21.4cb 19.7), NSMT-Cr 20822; B, Latreillopsis
laciniata Sakai, 1936, female (cl 11.6cb 8.3), NSMT-Cr 20823; C, Calappa gallus (Herbst, 1803), female(cl 19.4cb 24.1), NSMT-Cr 20824; D, Heteronucia fujitai sp. nov., holotype ovig. female (cl 11.5cb 12.9mm), NSMT-Cr 20825; E, Nucia speciosa Dana, 1852, female (cl 12.2cb 13.7), NSMT-Cr 20826; F, Raylilia uenoi (Takeda, 1995), female (cl 12.0cb 13.1), NSMT-Cr 20827. (Photo: Y. Fujita)ridge; epipod reduced, translucent on distal half;
podobranch absent.
Cheliped (Fig. 2B) moderate, 1.3 times as longas carapace, sparsely furnished with very short,plumose setae; coxal condyle subcircular; merus

and carpus subcylindrical, covered with large,
pearly granules; palm convex dorsally, slightly
constricted distally, covered with pearly granules,
granules smaller than those of merus and carpus;
fingers weak, about 0.8 times as long as palm,

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Hironori Komatsu and Masatsune Takeda

Fig. 2. Heteronucia fujitai sp. nov., holotype ovig. female (cl 11.5cb 12.9), NSMT-Cr 20825. A, frontal region, ventral view; B, left chela, dorsal view; C, right first ambulatory leg, posterior view; D, abdomen, ventral view. Scales: 1 mm.

with gap between cutting edges along proximal
0.8 when closed, with thin, fine teeth along both
cutting edges, teeth continuous in distal 0.7.
Ambulatory legs (Fig. 2C) moderate length,
similar in shape, gradually decreasing in lengthfrom first to fourth, covered with small, rounded
granules except dactyli, sparsely furnished withshort plumose setae; coxal condyles rounded;meri and carpi subcylindrical; propodi weakly
compressed; dactyli subconical, with smooth
dactylo-propodal locks on proximal ends of dorsal surfaces, covered with inconspicuous, micro-

scopic granules.
Thoracic sternites covered with rounded granules of various sizes; first to fourth sternites
fused; fourth to eighth sternites with medially interrupted sutures between sternites; abdominal
cavity reaching to buccal cavity.
Abdomen (Fig. 2D) covered with rounded
granules of various sizes; first segment completely concealed beneath carapace; second and third
segments short, transversely subrectangular;
main fused section composed of fourth to sixth
segments, ovate, moderately convex ventrally;Rare Crabs from Okinawa Island

129

Fig. 3. Right mouth parts of Heteronucia fujitai sp. nov., holotype ovig. female (cl 11.5cb 12.9), NSMT-Cr
20825. A, mandible, external view; B, same, internal view; C, maxillule, external view; D, maxilla, externalview; E, first maxilliped, external view; F, second maxilliped, external view; G, third maxilliped, externalview; H, same, internal view. Scale: 1 mm.

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Hironori Komatsu and Masatsune Takeda

Fig. 4. A–B, Heteronucia fujitai sp. nov., holotype ovig. female (cl 11.5cb 12.9), NSMT-Cr 20825; C–D,
Pseudolambrus longispinosus (Flipse, 1930), female (cl 16.9cb 18.2), NSMT-Cr 20833.

telson tongue-shaped, fringed with very shortsetae.
Color. Dorsal surfaces of carapace, chelipeds
and ambulatory legs cream, symmetricallyspeckled with red punctae.
Etymology. This species was named after Dr.
Yoshihisa Fujita of the University of the Ryukyus
who kindly provided us the specimens for study.
Remarks. Heteronucia fujitai sp. nov. is similar
to H. laminata (Doflein, 1904) in the grobular
carapace with only divided intestinal region, but
can be distinguished from H. laminata by that (1)the carapace is broader than long (vs. longer thanbroad in H. laminata); (2) the ambulatory legs
have no laminar margin (vs. the merus, carpus
and propodus of the fourth ambulatory leg havelaminar inner margins in H. laminata); (3) the
first segment of the female abdomen is completely concealed beneath the carapace (vs. appeared

to be very short in H. laminata). This species isalso photographed as Nucia sp. by Minemizu(2000) from Miyako Island, the Ryukyu Islands,
at the depth of 6 m. Although the specimen was
not collected, the photograph clearly shows that
his species belongs to the present new species.
Distribution. Known only from Okinawa Island and Miyako Island, the Ryukyu Islands, occurring at depth of 6 m.
Nucia speciosa Dana, 1852
[Japanese name: Ibo-tsubu-kobushi](Fig. 1E)

Material examined. Cape Maeda, Onna, Okinawa I., 2 m deep; 1 / (cl 12.2cb 13.7), NSMTCr 20826; 19 May 1998.
Distribution. Whole Indo-West Pacific (Chenand Sun 2002).

Rare Crabs from Okinawa Island

131

Raylilia uenoi (Takeda, 1995)

Urnalana insularis: Galil, 2005, p. 24, figs. 2D, 7A.

[Japanese name: Ueno-kobushi]

Material examined. Mizugama, Kadena, Okinawa I., 3 m deep; 1 young / (cl 7.7cb 8.0),
NSMT-Cr 20828; 9 October 1996.
Remarks. Galil (2005) transferred this species
to the new genus Urnalana and compared withthe closely related U. elata (A. Milne Edwards)
to which Leucosia sagamiensis Sakai and L.
bikiniensis Sakai were synonymized. The specimen examined is a young female, so that it is impossible to compare the first male pleopod, but
the contour of the carapace is seemingly different, with the longer posterolateral margin of thecarapace in U. elata. Another congener, U. elatula Galil is also close to this species in the generalshape of the carapace, but mentioned that the anterolateral margin of the carapace is angled andthe third maxilliped coxa in female has a conicaltubercle. In the present female the anterolateral
margin of the carapace is not always nearly
oblique, but also more or less angled, but thethird maxilliped coxa is quite smooth.
Distribution. Japan, Mariana Is., Fiji, New
Caledonia, Loyalty Is., Chesterfield Is., 1–200 m
deep (Galil, 2005).

(Fig. 1F)
Arcania uenoi Takeda, 1995, p. 151, figs. 1–2.
Raylilia uenoi: Galil, 2001, p. 73, figs. 7–8.

Material examined. Cape Maeda, Onna, Okinawa I., 8 m deep; 1/ (cl 12.0cb 13.1), NSMTCr 20827; 4 August 2004.
Remarks. The specimen at hand is a female ofgood size and generally agrees well with the previous descriptions except for the mesobranchial
tubercle shorter than the male specimens. This
species was originally referred to the genus Arcania, and later included in the genus Raylilia
newly established by Galil (2001) together with
Arcania gracilipes Bell, Randallia mirabilis
Zarenkov and Raylilia coniculifera Galil. According to Galil (2001), Raylilia is distinguishedfrom Arcania by having the basal antennular segment entirely sealing the antennular fossa, theanterior margin of the efferent branchial channel
medially fissured and separated from the orbital
margin by a deep groove, the posterior margin of
the carapace tridenticulate, the third to sixth segments of the male abdomen fused and bearing apreapical tubercle, and the first male pleopod distally expanded lamellate.
This species differs from the congeners mostremarkably in having a strong mesobranchial tubercle directed obliquely backward and longer
than the intestinal tubercle. The first male pleopod is characteristic in having the widened petalshaped tip evenly denticulate along the margin.
Distribution. This species was originally reported from Ie-jima Island in the Ryukyu Islands,
35 m deep, and later from the Sulu Archipelago,Java, Chesterfield Island, New Caledonia andMadagascar, 30–65 m deep.
Urnalana insularis (Takeda and Kurata, 1976)[Japanese name: Ogasawara-kobushi](Fig. 5A)
Leucosia insularis Takeda and Kurata 1976, p. 21, figs. 1,
3a, pl. 1 fig. 1; Ovaere, 1987, p. 185.

Urnalana purarensis (Ovaere, 1987)[Japanese name: Kume-jima-kobushi](Fig. 5B)
Leucosia purarensis Ovaere, 1987, p. 192, figs. 2b, 6a;Marumura and Kosaka, 2003, p. 29, fig. 13.
Urnalana purarensis: Galil, 2005, p. 30, figs. 3B, 8B.

Material examined. Cape Maeda, Onna, Okinawa I., 3 m deep; 1? (cl 7.3cb 7.6), NSMT-Cr
20829; 4 May 1998.
Remarks. This is the second record of thisspecies from Japanese waters. Marumura andKosaka (2003) listed this species from Kume Island, Kerama Group, the Rhyukyu Islands, 15–20
m deep, with a color photograph. The female
specimen was examined by the junior author at
the Wakayama Prefectural Museum of Natural
History. These specimens agree well with theoriginal description (Ovaere, 1987) and the sub-

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Hironori Komatsu and Masatsune Takeda

Fig. 5. A, Urnalana insularis (Takeda and Kurata, 1976), young female (cl 7.7cb 8.0), NSMT-Cr 20828; B,
Urnalana purarensis (Ovaere, 1987), male (cl 7.3cb 7.6), NSMT-Cr 20829; C, Drachiella caelata Takeda
and Tachikawa, 1995, female (cl 14.9cb 20.0), NSMT-Cr 20830; D, Furtipodia petrosa (Klunzinger, 1906),
male (cl 15.9cb 23.9), NSMT-Cr 20831; E, Pseudolambrus longispinosus (Flipse, 1930), female (cl16.9cb 18.2), NSMT-Cr 20833; F, Crossotonotus spinipes (De Man, 1888), female (cl 32.3cb 37.3),
NSMT-Cr 20834. (Photo: Y. Fujita)

sequent description by Galil (2005).
Distribution. Japan, Taiwan, Papua New
Guinea (type locality), Guam, Tahiti, Tuamotu
Archipelago, occurring at the depths of 0–12 m(Galil, 2005; present study).

Family Aethridae
Drachiella caelata Takeda and Tachikawa, 1995
[Japanese name: Ukibori-mizo-kobushi](Figs. 5C, 6)
Drachiella caelata Takeda and Tachikawa, 1995, p. 212,

Rare Crabs from Okinawa Island
fig. 1.

Material examined. Mizugama, Kadena, Okinawa I., 8.2 m deep; 1/ (cl 14.9cb 20.0),
NSMT-Cr 20830; 7 August 1998.
Supplementary description. Mandible well calcified; cutting edge triangular in outline, pointed
medially; endopod palp 3-segmented, first segment very short, fringed with short setae on ter-

133

minal segment. Maxillule: coxal endite rod-like,directed mesially, densely fringed with stout andthin setae on lateral margin; basial endite triangular, fringed with stout and thin setae on mesial
margin, with some weakly plumose setae on lateral margin; endopod stilliform, unsegmented,
with some plumose setae on proximal part of lateral margin. Maxilla: coxal endite roundly

Fig. 6. Drachiella caelata Takeda and Tachikawa, 1995, female (cl 14.9cb 20.0), NSMT-Cr 20830. A, rightthird maxilliped, external view; B, same, internal view; C, left chela, dorsal view; D, right first ambulatoryleg, posterior view; E, abdomen, ventral view. Scales: 1 mm.

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Hironori Komatsu and Masatsune Takeda

bilobed; basial endite narrow, elongate triangular,
with some terminal setae; endopod tongueshaped; exopod (scaphognathite) longitudinallyexpanded into oval structure, entirely fringed
with short, plumose setae. First maxilliped: coxal
endite rounded, with dense, weakly plumose
setae; basial endite subtriangular, densely fringed
with moderately long, plumose setae; endopod
longitudinally expanded, rounded at apex, fittingin efferent channel, fringed with short setae
along margin of distal half, carinate on upper surface; exopod longitudinally filiform, bearing flagellum with some terminal setae. Second maxilliped fringed with long plumose setae alongmesial margin of ischium and merus and lateral
margin of merus; propodus and dactylus densely
fringed with long setae, setae around tip ofdactylus stout; exopod narrow, tapering distally,
fringed with short plumose setae on proximal
half of lateral margin, bearing flagellum withsome terminal setae; exodite rounded.
Third maxilliped (Fig. 6A–B) covered withcoarse, rounded granules of various sizes; basis
fused with ischium but with suture on internalsurface; ischium subsquamate; merus moderately
bent dorsally in situ, about 0.60 times as long as
ischium along mesial margin; dactylus with distally denticulate, stout setae along inner margin;
exopod subsquamate, rounded at tip, fringed withshort setae along lateral margin; internal exopodal ridge prominent, with short setae along ridge;
epipod reduced, translucent on distal half;
podobranch absent.
Cheliped (Fig. 6C) moderate, 1.1 times as longas carapace, covered with rounded granules ofvarious sizes; coxal condyle rounded; merus andcarpus subcylindrical; palm broad, convex dorsally; movable finger subconical, about as long aspalm, without gap between cutting edges whenclosed; immovable finger blade-like, about twiceas broad as movable finger; both cutting edges
with triangular teeth of various sizes.
Ambulatory legs (Fig. 6D) short, similar inshape, gradually decreasing in length from 1st to
4th, coarsely covered with granules of various
sizes and shapes; coxal condyles rounded; meri,

carpi, and propodi subcylindrical, with acutegranules on outer surfaces; dactyli subconical,
without dactylo-propodal locks.
Abdomen (Fig. 6E) longitudinally ovoid; allsegments divided from each other, but 2nd to 6th
segments are fused together and immovable; 1stsegment very short, transversely linear; 2nd to
6th segments short, almost same length, transversely subrectangular, covered with pearly granules of various sizes; telson subtriangular, tip
tongue-shaped.
Remarks. This is the second record of thisspecies since the original description from theOgasawara Islands. The type specimens are only
empty shell without all appendages and abdomen, therefore this is the first live specimen of
this species. The present specimen agrees wellwith the original description in the characteristic
areolation of the upper surface of the carapace.
Supplementary description of the mouthparts,
pereiopods, and female abdomen is provided inthis paper.
Recently Ng et al. (2008) removed the genus
Drachiella from the family Leucosiidae to thefamily Aethridae. But the shape of the mouthparts and the afferent channel suggests this genus
belongs to the family Leucosiidae. To clarify thetaxonomic position of Drachiella, further phylogenetic analysis is needed.
Distribution. Known only from Ogasawara Is.
and Ryukyu Is., Japan, at the depths of 6–8 m.
Family Parthenopidae
Furtipodia petrosa (Klunzinger, 1906)[New Japanese name: Gareba-hishi-gani](Fig. 5D)
Heterocrypta petrosa Klunzinger, 1906, p. 53, pl. 2(9);Lenz, 1910: 543.
Furtipodia petrosa: Tan and Ng, 2003, p. 403, figs. 4b,5c–d.
Daldorfia horrida: Hoover, 1998, p. 271, photo (b). [Not
Cancer horridus Linnaeus, 1758]

Material examined. Cape Maeda, Onna, Okinawa I., 9 m deep; 1? (cl 15.9cb 23.9), NSMTCr 20831; 6 August 1998.

Rare Crabs from Okinawa Island

Additional material examined. One empty
shell (cl 15.9cb 24.2), NSMT-Cr 20832, Kita
Port, Haha-jima I., Ogasawara Is., southern
Japan, pebble beach, under the rock, 1 m deep,coll. T. Kaneko, 21 Aug. 2008.
Remarks. The present specimen agrees wellwith the original description and the figures of
Tan and Ng (2003). This is the first record of thisspecies from Japanese waters. It is also noted atpresent that a male (cl 14.4cb 21.5, WMNHNa-Cr469) from Kuroshima Island, the Ryukyu
Islands, was examined by the junior author at the
Wakayama Prefectural Museum of Natural History. The specimen in the Nagai Collection wasrecorded by Marumura and Kosaka (2003) as
Heterocrypta sp. In addition, this species was
also collected from Haha Island, the Ogasawara
Islands, by Mr. Takaaki Kaneko, a student of theTokyo University of Marine Science and Technology. Unforthnately, other crabs fed on thisspecimen during the collecting work, therefore
the empty shell of the carapace and the large,
right cheliped were extant.
Distribution. Seychelles, Yemen, Red Sea(type locality), Sri Lanka, New Caledonia, Australia, Guam, Japan, Hawaii, occurring at intertidal water to 62 m (Tan and Ng, 2003; present
study).

135

carapace (Fig. 4D) indicates the remarkable
length of the tubercles and the depressedbranchial region ornamented with a ridge running from the posterolateral angle. The height
and thickness of the tubercles may be variable,
but the lobular armature of the chelipeds is also
close to the original figure.
Takeda (1976) mentioned the occurrence ofPseudolambrus hepatoconus Flipse in the shallow water off Mage-jima Island, southwesternJapan, but Takeda (1977) changed its identification to Ps. longispinosus (Flipse). The specimen
is characteristic in having thick, more or lesselongated knobbed tubercles each at the mesogastric and cardiac regions and also some
knobbed tubercles at the branchial region. On examination of the specimen Dr. S. H. Tan of the
University of Singapore corrected its identification as Ps. longispinosus to Ps. hepatoconus.
Distribution. This species is known only by
the heliotype male from Sanguisiapo, 12 m deep,
without subsequent record. Based on the present
record, this species is rightly included in the carcinological fauna of Japan, together with
Pseudolambrus hepatoconus (Flipse) from
Mage-jima Island, southwestern Japan wrongly
recorded as Ps. longispinosus by Takeda (1977).
Family Palicidae

Pseudolambrus longispinosus (Flipse, 1930)

Crossotonotus spinipes (De Man, 1888)[New Japanese name: Togenaga-hishi-gani][Japanese name: Ashibuto-itoashi-gani](Figs. 4C–D, 5E)(Fig. 5F)

Lambrus(Pseudolambrus)
hepatoconus
var.
longispinosus Flipse, 1930, p. 59, fig. 35.
Not Pseudolambrus longispinosus: Takeda 1977, p. 77,
figs. 2, 11-12. [Ps. hepatoconus (Flipse, 1930)]

Material examined. Mizugama, Kadena, Okinawa I., 4 m deep; 1/ (cl 32.3cb 37.3), NSMTCr 20834; 7 August 1996.
Distribution. Whole Indo-West Pacific (Castro,
2000).

Material examined. Cape Maeda, Onna, Okinawa I., 8 m deep; 1/ (cl 16.9cb 18.2), NSMTCr 20833; 2 August 1998.
Remarks. This species is, as seen in the photographs (Fig. 4C–D), very characteristic in having two long, erect tubercles in the median line at
the mesogastric and cardiac regions. The mesogastric tubercle is about twice as long and thickas the cardiac tubercle. The lateral view of the

Acknowledgments
We wish to express our cordial thanks to Dr.
Yoshihisa Fujita of the University of the Ryukyus
for providing us the specimens and the color photographs. Our thanks are also due to Mr. Takaaki
Kaneko of the Tokyo University of Marine Sci-

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Hironori Komatsu and Masatsune Takeda

ence and Technology for offering the specimen,
and the authority of the Wakayama Prefectural
Museum of Natural History for the permit to examine the specimens in the Nagai Collection.
References
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Indo-west Pacific species of palicid crabs (Brachyura
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Chen H. and H. Sun, 2002. Arthropoda Crustacea
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