Bull. Natl. Mus. Nat. Sci., Ser. A, 44(3), pp. 87–92, August 22, 2018

A New King Crab of the Genus Lithodes Latreille, 1806(Crustacea, Decapoda, Anomura, Lithodidae) from Indonesia
Masatsune Takeda
Department of Zoology, National Museum of Nature and Science,
4–4–1 Amakubo, Tsukuba, Ibaraki 305–0005, Japan
E-mail: takeda@kahaku.go.jp(Received 22 June 2018; accepted 28 June 2018)

Abstract A female king crab of the genus Lithodes Latreille, 1806 (Crustacea, Decapoda, Anomura, Lithodidae) from the Indonesian depths (Ceram Sea, 1,000–1,500 m deep) is described as
new to science under the name of L. ahyongi. The new species is close to L. richeri Macpherson,
1990 from the South Paciﬁc (Vanuatu, New Caledonia, and eastern Australia, 860–1,220 m deep),in having the long rod–like rostrum, but characterized by the wider carapace with much stronger
dorsal and marginal tubercles.
Key words: Lithodidae, Lithodes, king crab, new species, Ceram Sea, Indonesia.

Introduction
Takeda and Nagai (2004) recorded four crustacean species of enormous sizes from the depthsof 1,000–1,500 m in the Ceram Sea, Indonesia,Acanthacaris tenuimana Bate, 1888 (Macrura,Nephropidae), Lithodes ceramensis sp. nov. andL. richeri Macpherson, 1990 (Anomura, Lithodidae), and Chaceon karubar Manning, 1993
(Brachyura, Geryonidae). Of them, the identiﬁcation of a female king crab as L. richeri was rathertentative, as the carapace contour is somewhat
different from those of the type specimens, fourmales from New Caledonia. Later, Ahyong(2010) suggested that the difference in the carapace contour is not individual and developmental, but speciﬁc, with the comparative examination of many specimens of different sizes
referable to L. richeri.
The female specimen reported by Takeda andNagai (2004) as L. richeri was reexamined following the suggestion of Ahyong (2010), and thespeciﬁc validity was conﬁrmed. The purpose ofthis paper is to describe the Indonesian deep-sea
specimen from the Ceram Sea as a new species.

In the following description of the new species,
the terminology basically follows Ahyong(2010), except that the words of tubercles areadopted for deﬁnite image instead of the wordsof spines.
The holotype is in the collections of theNational Museum of Nature and Science, Tokyo(NSMT).
Family LITHODIDAE
Genus Lithodes Latreille, 1806
Lithodes ahyongi sp. nov.
(Figs. 1–2)
Lithodes richer: Takeda and Nagai, 2004, p. 15, ﬁgs. 5–6.
[Not L. richeri Macpherson, 1990]

Material examined. Off Wahai, Ceram
Island, Moluccas, Indonesia, 1,000–1,500 m
deep; female (holotype), NSMT–Cr 15694;
October 1993, coll. by local ﬁsherman. The specimen was once dried, and later restored and kept
in 70% ethanol following the method for restoring dried crustacean specimens with ethylene
glycol reported by Thompson et al. (1966).

88M. Takeda

Fig. 1. Lithodes ahyongi sp. nov., holotype, female (NSMT–Cr 15694), 175 mm in postorbital carapace length.
A–C: Carapace in different angles to show the contour and tuberculation (B: after Takeda and Nagai, 2004,
ﬁg. 6A).

Measurements. Postorbital carapace length,
175 mm; rostral length including distal branch,
134 mm; carapace width excluding marginal
branchial spines, 165 mm; greatest width of carapace including marginal branchial spines(between ﬁrst primary marginal branchial spinesof both sides), 175 mm. Total length of left ﬁrst
ambulatory legs, 415 mm (ischium＋merus,155 mm; carpus, 75 mm; propodus, 120 mm; dactylus, 65 mm); total length of left second ambulatory leg, 445 mm (ischium＋merus, 165 mm; carpus, 75 mm; propodus, 135 mm; dactylus,70 mm).
Diagnosis. Species close to Lithodes richeri
Macpherson, 1990. Rostrum long, rod–like, morethan two thirds as long as postorbital carapace.
Postorbital carapace length equal to greatest

breadth of carapace between ﬁrst primary marginal branchial spine of both sides. Gastric,hepatic and branchial regions distinct, strongly
convex dorsally, each with some symmetricallyarranged papillate tubercles.
Description of holotype. Carapace (Figs. 1,2A–B, F): Postorbital carapace hardly longer
than carapace width between base of ﬁrst primary marginal branchial spine of both sides, andstrictly equal to greatest width of carapace
between tip of ﬁrst primary marginal brnchialspine of both sides; hepatic margin shallowly
concave, weakly divergent toward hepatic tubercle; right hepatic tubercle abnormal in shape,with a big swell; left branchial tubercle swollen
at base, sharply pointed at tip, directed laterally;
posterior slope of hepatic tubercle and anterior

A New King Crab of the Genus Lithodes from Indonesia

89Fig. 2. Lithodes ahyongi sp. nov., holotype, female (NSMT–Cr15694), 175 mm in postorbital carapace length. A,
B: Carapace in different angles. C: Abdomen. D: Both chelae in outer view. E: Distal three articles of left ﬁrst
and second ambulatory legs. F: Carapace with detached chelipeds and ambulatory legs (after Takeda andNagai, 2004, ﬁg. 6B).

branchial margin right-angled; anterior branchial
margin straight, obliquely divergent toward ﬁrst
primary marginal branchial spine, taking one
fourth as long as whole branchial margin; lateraland posterior branchial margins of both sides andintestinal margin distinctly subcircular in outline,
thickened with submarginal depression, armed

with several equidistant, small marginal tubercles; ﬁrst primary marginal branchial spine wide
at base, spiniform distally, making an anterolateral angle of branchial margin; second primary
marginal branchial spine not prominent, hardly
larger than other marginal tubercles.
Gastric, hepatic, cardiac and branchial regions

90M. Takeda

convex, covered with small warty, uniformly
scattered granules of various sizes giving appearance of rough surface. Gastric region prominent,
as high as branchial regions, oblong, armed withtwo pairs of stout, more or less papillate tubercles with sharp tip; anterior pair of tubercles
slightly larger than the posterior; left tubercle ofanterior pair obtuse at tip, tip of right side
directed obliquely forward and outward; both
tubercles of posterior pair suberect or weakly
directed outward and backward, with distance
between two tubercles being narrower than thatof anterior pair.
Cardiac region armed with a pair of conical orsomewhat papillate tubercles side by side, withsharp tip; anterior slope armed with a pair ofsmall, but sharp subsidiary tubercles side by sidecloser to a deep transverse depression between
cardiac and gastric regions; a longitudinal linear
furrow sharply delimits boundary of cardiac andbranchial regions at each side, extending anteriorly along posterior half of gastric region toward
constriction between hepatic and branchial margins; liner furrows of both sides of cardiac region
parallel to each other, strongly converging posteriorly to form an posterior appendix region.
Intestinal region rather depressed, not distinctly delimited, divided into two with a medianlongitudinal linear furrow from cardiac posterior
appendix region along anterior half; intestinal
carapace margin with a small spine–tipped tubercle at each lateral end; distance between tips ofboth spines wider than that of cardiac spines, andsubequl to that of posterior pair of gastric spines.
Branchial region inﬂated most strongly atanterior spine; anterior branchial spine directed
obliquely outward, arising from a broad papillate
base; posterior spine short, with a small base,being placed at posterior one third, obliquely
behind anterior spine; third spine small, tubercular, placed close to posterior end of cardiac
region.
Rostrum (Figs. 1, 2A–B, F): Rod–like, morethan two thirds of postorbital carapace length,
directed obliquely upward, biﬁd at tip, armed
with a pair of dorsolateral spiniform tubercles;

proximal part to dorsolateral spines, about atbasal one third, more strongly directed upward;
distal branch about one and half times as long as
dorsolateral spine, straight, directed obliquely
downward; distal half of right branch broken off;a small tubercle at each side of base of rostrum.
Outer orbital spine tubercular, directed forward;
anterolateral spine tubercular, sharp at tip,
directed obliquely forward, with tip reachingslightly behind level of tip of outer orbital spine.
Chelipeds (Fig. 2D, F): Slender, with the rightbeing slightly larger. Ischium armed with twostrong tubercles arranged fore and aft alonglower margin, the former being twice as long as
the posterior; lower margin of ischium slightly
longer than lower margin of merus, about half as
long as upper margin of merus. Merus armed
with one strong terminal tubercle and three orfour small tubercles on upper margin, two indistinct tubercles on outer surface, and one strong
and some accessory tubercles on lower margin.
Carpus as long as lower margin of merus, withseveral tubercles; two on distal margin and two
on outer part stronger, the outer proximal one
being the longest. Palm armed with some small
tubercles on outer margin and on median part ofouter surface; those on outer surface more or lessarranged in two rows. In right (larger) chela,
upper margin of palm two thirds as long as upper
margin of movable ﬁnger; ﬁngers weakly curved
inward, with inner surfaces excavated, armed
with two or three sharp teeth on cutting edges
and many tufts of bristles along cutting edges. Inleft (smaller) chela, movable ﬁnger twice as longas upper margin of palm; ﬁngers armed with aseries of minute teeth, without large teeth.
Ambulatory legs (Fig. 2E–F): Incomplete
except for ﬁrst and second pairs. Both pairs slender, second pair longer than the ﬁrst. Eachischium armed with two tubercles, one on outersurface and the other on subdistal part of lower
margin. Each merus armed with three spines on
upper margin, the proximalmost being smaller
and becoming obsolete; terminal spine of uppermargin strongly developed; outer surface armed
with several scattered small tubercles mainly on

A New King Crab of the Genus Lithodes from Indonesia

proximal half. Carpus slender, armed with asmall tubercle close to proximal part of upper
margin and a long subterminal spine that isdirected obliquely outward and forward and aslong as terminal spine of upper margin of merus.
Propodus slender, slightly narrowing distally,
armed with three or four small tubercles on upper
margin and several on lower margin; two or threetubercles each on upper and lower surfaces; terminal tubercle of upper margin distinct. Dactylus
slender, weakly curved, with anteroposteriorly
depressed distal claw; four proximal tubercles,viz., two on upper and two on lower surfaces
weakly developed so as to be tubercular anddirected distally.
Abdomen (Fig. 2C): Well developed, covers
whole sternal surface, twisted as usual.
Remarks. This species was recorded as
Lithodes richeri Macpherson, 1990, by Takeda
and Nagai (2004), with a little hesitation. The
sole female specimen (postorbital carapacelength, 175 mm) that was described as the holotype of the new species is much larger than, andits carapace contour differs somewhat from, theholotype male (postorbital carapace length,83 mm) of L. richeri. As noted by Takeda andNagai (2004), the carapace, the detached somewhat fragmentary chelipeds and ambulatory legs,
and the abdomen are available for study. They
were arranged to show the size balance (Takedaand Nagai, 2004, Fig. 6B; reproduced as Fig. 2F
in this paper). The holotype is kept in good preservation state, but the distal half of the rightbranch of rostral bifurcation is broken off (Figs.
1, 2A–B).
It is well known that in the family Lithodidae,
the shape, areolation and tuberculation of the carapace are remarkably variable according to thesize in most of the genera, not only Lithodes but
also Paralithodes, Paralomis and the relatedgenera. Considering these variations, Takeda andNagai (2004) concluded and made a commentthat in due time the large specimens from New
Caledonia and the small specimens from theCeram Sea will contribute to the deﬁnite identiﬁcation of the female in question.

91In the monographic studies on the Lithodidaeof New Zealand, Australia and the Ross Sea,Ahyong (2010) examined a long series of the L.
richeri specimens and clearly indicated withdetailed description and many photographs thatthe size of L. richeri is extended up to 143 mm in
the postorbital carapace length, the carapace contour is consistently narrow pyriform and different
from the Ceram Sea specimen, and that the dorsal tubercles are much smaller and not so strong
as in the Ceram Sea specimen. Following thesuggestion that the Ceram Sea specimen possibly
represents an undescribed species, the specimen
from the Ceram Sea in the collections of theNational Museum of Nature and Science, Tokyo,
is reexamined and the speciﬁc validity was conﬁrmed. The present new species is 30th in thegenus Lithodes.
Etymology. This species is dedicated to Dr.
Shane T. Ahyong of the Australian Museum.
Without his contribution to the Lithodidae in2010, this species has been known under the misidentiﬁed name by Takeda and Nagai (2004).
Acknowledgements
The author thanks Mr. Shinji Nagai, the specialist of coleopterous beetles, who kindly
donated the crustacean specimens from the Indonesian depths to the National Museum of Natureand Science, Tokyo.
References
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iconibus exemplisque plurimis explicata. Amand Koenig, Paris, pp. xvii＋302＋Emenda, pls. 24.
Macpherson, E. 1990. Crustacea Decapoda: On some species of Lithodidae from the western Paciﬁc. In Crosnier, A. (ed.): Résultats des Campagnes MUSORSTOM. Volume 6. Mémoires de Muséum NationaldʼHistoire Naturelle, Paris, Zoologie, 145: 217–226.
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M. Takeda
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