RAFFLES BULLETIN OF ZOOLOGY 2021
Taxonomy & Systematics
RAFFLES BULLETIN OF ZOOLOGY 69: 1–7

Date of publication: 12 January 2021
DOI: 10.26107/RBZ-2021-0001
http://zoobank.org/urn:lsid:zoobank.org:pub:F861B9E5-475A-4A3D-B2AC-B49646FA7CC9

A new species of the genus Arachnothelphusa Ng, 1991 (Crustacea:
Decapoda: Gecarcinucidae) from a limestone cave in Sarawak(Malaysian Borneo)
Jongkar Grinang1* & Peter K. L. Ng2
Abstract. A new species of cavernicolous gecarcinucid crab, Arachnothelphusa sarang, is described from alimestone cave in northern Sarawak, Malaysian Borneo. This increases the number of Arachnothelphusa species
to six. It is the second member in the genus that is known to primarily occupy limestone caves, the other being
A. rhadamanthysi Ng & Goh, 1987, from Gomantong in Sabah. Both species appear to be cavernicolous species
with pale body colouration in life.
Key words. Brachyura, taxonomy, Oriental region, freshwater crab, cavernicolous crab

INTRODUCTION

Chian National History Museum (former Raffles Museumof Biodiversity Research), National University of Singapore(ZRC); Sarawak Biodiversity Centre, Sarawak, Malaysia(SBC); Naturalis Biodiversity Center (former Rijksmuseum
van Natuurlijke Historie), Leiden, The Netherlands (RMNH);
and Senckenberg Museum und Forschungsinstitut, Frankfurt
am Main, Germany (SMF).

Currently, the Bornean gecarcinucid genus Arachnothelphusa
Ng, 1991, is represented by five species, viz. A. melanippe(De Man, 1899) [central Kalimantan], A. kadamaiana(Borradaile, 1900) [northern Sabah], A. rhadamanthysi
Ng & Goh, 1987 [eastern Sabah], A. terrapes Ng, 1991
[eastern Sabah], and A. merarapensis Grinang, Pui & Ng,
2015 [northern Sarawak] (Grinang et al., 2015; Ng & Ng,2018). Members of Arachnothelphusa live in a wide rangeof habitats, from tree-holes to the interior of limestone
caves. Of the five species, only A. rhadamanthysi has beenrecorded from limestone caves in Gomantong in Sabah.
We here describe a sixth species of Arachnothelphusa, A.
sarang, new species, and the second cavernicolous member
from a limestone cave system in Sarawak.

TAXONOMYFamily Gecarcinucidae Rathbun, 1904
Arachnothelphusa Ng, 1991
Type species. Potamon (Potamon) melanippe De Man, 1899,by original designation.

MATERIAL AND METHODS

Arachnothelphusa sarang, new species(Figs. 1A–F, 2A–G, 3A–E, 4A)

The terminology used essentially follows Ng (1988) and
Davie et al. (2015), with the abbreviations G1 and G2
used for the male first and second gonopods, respectively.
Measurements provided in millimetres are of the carapace
width and length, respectively. Specimens examined aredeposited in the Zoological Reference Collection, Lee Kong

Material examined. Holotype: male (20.4 × 14.7 mm)(ZRC 2020.0098), limestone cave, Bukit Sarang, Bintulu,
Sarawak, Malaysia, coll. H.H. Tan et al., 20 August 2005.
Paratypes: 1 male (18.7 × 14.8 mm), 4 females (15.8–19.8
× 12.0–15.8 mm) (ZRC 2020.0099), same data as holotype;10 males (7.4–11.2 × 5.8–9.6 mm), 7 females (7.5–12.7 ×
5.8–9.9 mm) (ZRC 2020.0100), limestone cave, Batu Gelam,
Bukit Sarang, Bintulu, Sarawak, Malaysia, coll. H.H. Tan,
20 August 2005; 1 male (12.1 × 9.9 mm), 1 female (12.9 ×
10.4 mm) (ZRC 2020.0351), limestone cave, Batu Kelelut,
Bukit Sarang, Bintulu, Sarawak, Malaysia, coll. H.H. Tan
et al., 18 August 2005.

Accepted by: Jose Christopher E. Mendoza
Institute of Biodiversity and Environmental Conservation, Universiti Malaysia
Sarawak, 94300 Kota Samarahan, Sarawak, Malaysia; Email: gjongkar@unimas.my(*corresponding author)

1

Lee Kong Chian Natural History Museum, Faculty of Science, National Universityof Singapore, 2 Conservatory Drive, Singapore 117377, Republic of Singapore

2Comparative material. Arachnothelphusa merarapensis
Grinang, Pui & Ng, 2015: Holotype male (22.5 × 16.8mm) (ZRC 2016.0297), water-filled tree-hole, ca. 100© National University of Singapore
ISSN 2345-7600 (electronic) | ISSN 0217-2445 (print)

1

Grinang & Ng: New species of Arachnothelphusa from limestone cave in Sarawak

Fig. 1. Arachnothelphusa sarang, new species. A, male (12.1 × 9.9 mm) (ZRC 2020.0351), Batu Rusa cave, Bukit Sarang, Bintulu,
Sarawak, Malaysia; B, female (12.9 × 10.4 mm) (ZRC 2020.0351), Batu Kelelut, Bukit Sarang, Bintulu, Sarawak, Malaysia, specimen;
C–E, paratype male (18.7 × 15.3 mm) (ZRC 2020.0099), Bukit Sarang, Bintulu, Sarawak, Malaysia; F, paratype female (15.8 × 11.8 mm)(ZRC 2020.0099), Bukit Sarang, Bintulu, Sarawak, Malaysia. A, B, photographed in situ; C, F, overall dorsal habitus; D, ventral view of
cephalothorax; E, frontal view of cephalothorax and chelae. Photographs: Tan Heok Hui.

cm above ground, steep dipterocarp forest, Merarap Hot
Spring Resort, Lawas, northern Sarawak, Malaysia, Borneo,
4°22′25.4″N 115°26′10.1″E, 485 m asl, coll. J. Grinang &Y.M. Pui, 31 October 2014; paratype female (19.9 × 15.2mm) (SBC.C.00376), water-filled hole of tree buttress, ca.
90 cm above ground, steep dipterocarp forest, Merarap Hot
Spring Resort, Lawas, northern Sarawak, Malaysia, Borneo,
4°22′16.5″N 115°26′12.4″E, 494 m asl, coll. J. Grinang &Y.M. Pui, 1 November 2014; 1 female (22.3 × 16.1 mm)(SBC.C.00377), water-filled hole of tree buttress, ca. 30 cm
above ground, same data as paratype, coll. Y.M. Pui, 27
February 2013. Arachnothelphusa kadamaiana (Borradaile,
1900): Holotype female (18.9 × 13.5 mm) (SMF 4281),
Kadamian River, Sabah, Malaysia, Borneo; 1 male (20.1 ×
14.9 mm) (SMF 4282), same data as holotype; 1 female (23.2

× 17.1 mm) (ZRC 2009.0094), Poring, Basin 1A, Sabah,
Borneo, coll. R.F. Inger et al., 12 August 1992; 3 males(21.1 × 15.8 mm, 22.8 × 16.5 mm, 25.3 × 18.5 mm) (ZRC
2002.0097), Crocker Range, Sabah, 5°27′N 116°03′E, coll.
I. Das, 24 April 2001. Arachnothelphusa aff. kadamaiana: 1
female (19.0 × 14.2 mm) (ZRC 2002.0098), Bako National
Park, Sarawak, coll. I. Das & L. Grismer, 27 March 2001.
Arachnothelphusa terrapes Ng, 1991: Holotype male (17.6
× 13.3 mm) (ZRC 1992.7918), Danum Valley Field Centre,
station 507, in dry stump on ridge, Lahad Datu, Sabah,
Borneo, leg. H.K. Voris, 23 October 1990; paratype female(25.7 × 18.6 mm) (ZRC 1992.7919), Danum Valley, Lahad
Datu, Sabah, Borneo, leg. S.C. Choy, 21 July 1989; others:
1 male (30.8 × 20.5 mm), 1 female (30.1 × 20.5 mm, with
26 juvenile crabs) (ZRC 2017.1205), from water-filled tree
2

RAFFLES BULLETIN OF ZOOLOGY 2021

Fig. 2. Arachnothelphusa sarang, new species. A–E, holotype male (20.4 × 14.7 mm) (ZRC 2020.0098), Bukit Sarang, Bintulu, Sarawak,
Malaysia; F, G, paratype female (19.8 × 15.8 mm) (ZRC 2020.0100), Bukit Sarang, Bintulu, Sarawak, Malaysia. A, F, dorsal view of
habitus; B, G, ventral view of carapace showing pleon; C, frontal view of cephalothorax; D, outer view of left chela; E, outer view ofright fourth ambulatory leg. Scales: A, B, C, F, G = 10 mm; D, E = 5 mm.

Females. The females differ in minor non-sexual charactersby the carapace being slightly broader and lower (Fig. 2F,
G). Female pleon broad, round, somite 6 subequal to lengthof telson, tip of telson round pointed (Fig. 2G). In larger
specimens of both sexes, the antero- and posterolateralregions have relatively more coarse granules. The vulvae
are transversely ovate, large, without obvious sternal vulvar
covers and are positioned on the median part thoracic ofsternite 6.

buttress, ca. 35 cm above ground Danum Valley, Lahad Datu,
Sabah, Borneo, Malaysia, 20 July 2017. Arachnothelphusa
melanippe (De Man, 1899): Lectotype male (18.9 × 14.4 mm)(RMNH D1303a), Liang Koebeng Mountains, Kalimantan,
leg. 1897; paralectotype female (21.4 × 16.7 mm) (RMNH
D1303b), same as lectotype.
Diagnosis. Carapace surface convex, rugose, finely
granular; anterolateral margins convex, serrated; antero- andposterolateral regions prominently rugose, covered withnumerous coarse granules; epibranchial tooth very low orindistinct; external orbital tooth very low, broadly triangular,outer margin slightly concave, distinctly serrated; epigastricand postorbital cristae distinct; cervical and H-grooves deep,
not confluent (Fig. 2A, C); ambulatory legs long, merus offourth ambulatory legs subequal to length of carapace (Fig.
2A, B, E); carpus of chelipeds rugose, with fine granules,
inner angle with broadly triangular tooth (Fig. 2A, D); chela
relatively short, fingers as long as palm, cutting teeth onpollex not prominent (Fig. 2D). Male pleon T-shaped, somite
6 subequal to length of telson (Fig. 2B). G1 slender, sinuous,
gently curving outwards; terminal segment cylindrical,
tapering, about one third length of subterminal segment (Fig.
3A–D). G2 with short distal segment, less than a quarter
length of basal segment (Fig. 3E).

Variation. The numerous paratype specimens agree wellwith the holotype male in non-sexual characters.
Colour. In life, the species is pale purplish brown to yellowish
in both sexes on the dorsal surfaces, the ventral surfaces
being pale yellow to dirty white. The corneas of the eyes
are large and fully pigmented (Fig. 1).
Etymology. The species is named after the locality where
the holotype was collected. The name is used as a noun inapposition.
Remarks. Arachnothelphusa sarang, new species, iseasily distinguished from A. merarapensis, A. terrapes,
A. melanippe, and A. rhadamanthysi by its very low toindistinct epibranchial tooth as well as the very low, broad
3

Grinang & Ng: New species of Arachnothelphusa from limestone cave in Sarawak

Fig. 3. Arachnothelphusa sarang, new species, holotype male (20.4 × 14.7 mm) (ZRC 2020.0098), limestone cave, Bukit Sarang, Bintulu,
Sarawak, Malaysia. A, dorsal view of left G1; B, dorsal view of distal part of left G1; C, ventral view of left G1; D, ventral view of distal
part of left G1; E, dorsal view of left G2. Scales = 0.5 mm.

external orbital tooth (Figs. 1C, F, 2A–C, F, G, 4A). In A.
merarapensis, the epibranchial tooth is acutely triangular,
separated from the external orbital tooth by a wide and deep
cleft and the external orbital tooth is acutely triangular (Fig.
4B; cf. Grinang et al., 2015: fig. 1A–C). In A. terrapes, theepibranchial tooth is distinct on both sides, separated fromthe external orbital tooth by a deep and broad U-shaped cleft
and the external orbital tooth is triangular (Fig. 4C; cf. Ng,
1991: fig. 3 [incorrectly printed as fig. 5]; cf. Ng & Ng, 2018:
fig. 5B–F). In A. melanippe, the epibranchial tooth is distinct
but relatively small and separated from the external orbital
tooth by a small cleft, with the external orbital tooth broadly
triangular (Fig. 4E; cf. De Man, 1899: pl. 9 fig. 11; Ng,
1991: fig. 1). In A. rhadamanthysi, the epibranchial tooth isdistinct on both sides with the external orbital tooth triangular(cf. Ng & Goh, 1987: pl. 3A, B). In carapace features, A.
sarang is perhaps closest to A. kadamaiana, but they canbe distinguished by the presence of a distinct epibranchial
tooth and a relatively more anteriorly projecting and acuteapex of the external orbital tooth for the latter (Figs. 2A–C,
F, G, 4A versus Fig. 4D; cf. Grinang et al., 2015: fig. 6A).
The anterolateral region of A. sarang is distinctly less rugosewith fine granules, whereas this region is prominently rugosewith coarse granules for congeners (Fig. 4A versus 4B–E).
The structure of the G1 of A. sarang differs from that of A.
terrapes and A. melanippe in gently curving outwards (Fig.
3A–D) versus distinctly curving outwards in the latter two
species (Fig. 5F–I, O–R). In the G1 structure, A. sarang issimilar to A. merarapensis and A. kadamaiana, but they
can be distinguished by the following features: the terminal
segment of the G1 of A. sarang and A. kadamaiana is
about one-third the length of the subterminal segment (Figs.

3A–D, 5K–M); while that of A. merarapensis is about half
the length of the subterminal segment (Fig. 5A–D). The
distal segment of the G2 of A. sarang and A. merarapensis
is less than a quarter the length of the basal segment (Figs.
3E, 5E), but in A. kadamaiana, it is less than one-fifth thelength of the basal segment (Fig. 4N). The gonopods of A.
rhadamanthysi are not known.
The live colouration of the two cave species differs markedly
from those of the epigeal species. The live colouration of A.
sarang, new species, ranges from light purplish to yellowish
brown (Fig. 1). This is similar to that known for the othercavernicolous species, A. rhadamanthysi, which is palestraw-yellow with white legs (Fig. 6; cf. Ng & Goh, 1987:
326). Arachnothelphusa merarapensis is bright purple overall(cf. Grinang et al., 2015: fig. 3A, B), whereas A. terrapes isbrown to reddish-brown (cf. Ng, 1991: figs. 4, 5 [not labelled
in original paper]; Ng & Ng, 2018: fig. 5B–E). The habits
and live colouration of A. melanippe and A. kadamaiana
are not known.
The habitat, pale colouration in life, and general appearanceof Arachnothelphusa sarang, new species, are also similar
to those of the genus Stygothelphusa Ng, 1989, whichcontains four species, all from limestone caves in Sarawak(Ng, 1991, 2013; Ng & Grinang, 2014). The carapaceof Stygothelphusa, however, is generally more quadrate(versus more transversely ovate in Arachnothelphusa), theambulatory legs are proportionately even longer, and mostsignificantly, the G2 is much longer than the G1, with the
distal segment long and flagelliform (versus G2 shorter thanG1, with the distal segment short in Arachnothelphusa).
4

RAFFLES BULLETIN OF ZOOLOGY 2021

Fig. 4. Carapace morphology of Arachnothelphusa species. A, A. sarang, new species, holotype male (20.4 × 14.7 mm) (ZRC 2020.0098),
limestone cave, Bukit Sarang, Bintulu, Sarawak; B, A. merarapensis Grinang, Pui & Ng, 2015, holotype male (22.5 × 16.8 mm) (ZRC
2016.0297), Merarap Hot Spring, Lawas, Sarawak; C, A. terrapes Ng, 1991, male (30.8 × 20.5 mm) (ZRC 2017.1205), Danum Valley,
Lahad Datu, Sabah; D, A. kadamaiana (Borradaile, 1900), male (20.1 × 14.9 mm) (SMF 4282), Kadamian River, Sabah; E, A. melanippe(De Man, 1899), paratype female (21.4 × 16.7 mm) (RMNH D1303b), Mt. Liang Koebeng, Kalimantan, Indonesia. E after Ng (1991).

Fig. 5. Gonopod morphology of Arachnothelphusa species. A–E, A. merarapensis Grinang, Pui & Ng, 2015, holotype, male (22.5 ×
16.8 mm) (ZRC 2016.0297), Merarap Hot Spring, Lawas, Sarawak; F–J, A. terrapes Ng, 1991, holotype, male (17.6 × 13.3 mm) (ZRC
1992.7918), Danum Valley, Lahad Datu, Sabah; K–N, A. kadamaiana (Borradaile, 1900), male (20.1 × 14.9 mm) (SMF 4282), KadamianRiver, Sabah; O–S, A. melanippe (De Man, 1899), lectotype, male (18.9 × 14.4 mm) (RMNH D1303a), Mt. Liang Koebeng, Kalimantan,
Borneo. C, F, K, O, ventral view of left G1; D, G, L, P, ventral view of distal part of left G1; A, H, Q, dorsal view of left G1; B, I, M,
R, ventral view of distal part of left G1; E, J, N, S, left G2. A–E, K–N after Grinang et al. (2015); F–J, O–S after Ng (1991).

5

Grinang & Ng: New species of Arachnothelphusa from limestone cave in Sarawak
hill surrounded by peat swamp, comprises a complex ofsmall caves with different names, most of which are almost
certainly with subterranean interconnections, and is part of
the Tatau River basin. All the specimens of A. sarang were
found in water pools with fine substrates, and co-existingwith whelk snails, several hundred metres from the caveentrance; none were observed near the cave mouth (H. H.
Tan, pers. comm.). The limestone cave of Bukit Sarang is
a protected area and important for sustainable edible birdnest production. The harvesting of bird-nests will have to
be done carefully so as not to pollute or disturb the habitat
if the crab is to be conserved.
Key to species of Arachnothelphusa of Borneo
1. Epibranchial tooth very low or indistinct; external orbital toothvery low, broad; anterolateral region less rugose, fine granules,
carapace surface smooth (Figs. 1C, F, 2A, B, C, F, G, 4A);
G1 gently curving outwards, terminal segment about one-third
length of subterminal segment; distal segment of G2 less thana quarter length of basal segment (Fig. 3A–E).........................
............................ A. sarang, new species (northern Sarawak)– Epibranchial tooth distinct, triangular; external orbital tooth
triangular; anterolateral region prominently rugose, coarse
granules, carapace surface rugose (Fig. 4B–E); G1 gently orstrongly curving outwards, terminal segment either half, onethird or a quarter length of subterminal segment; distal segmentof G2 either a quarter or one-fifth length of basal segment (Fig.
5)...............................................................................................2
2. Epibranchial tooth distinct, acutely triangular; G1 strongly
curving outwards (Fig. 5F, H, O, Q).......................................3– Epibranchial tooth distinct, relatively blunt; G1 gently curving
outwards (Fig. 5A, C, K).........................................................4
3. Epibranchial tooth acutely triangular, distinctly separated fromexternal orbital tooth by wide, deep cleft; external orbital
acutely triangular (Fig. 4B); terminal segment of G1 about
half of length of subterminal segment; distal segment of G2
about quarter length of basal segment (Fig. 5A–E)..................
....................................... A. merarapensis (northern Sarawak)– Epibranchial tooth distinct but relatively small, separated fromexternal orbital tooth by small cleft; external orbital toothbroadly triangular (Fig. 4E); terminal segment of G1 about
one-third of length of subterminal segment; distal segment
less than a quarter length of basal segment (Fig. 5O–S)..........
.......................................... A. melanippe (central Kalimantan)
4. Epibranchial tooth distinct; external orbital tooth broadly
triangular (Fig. 4D); terminal segment of G1 about a third
length of subterminal segment (Fig. 5K–M).............................
............................................. A. kadamaiana (northern Sabah)– Epibranchial tooth distinct; external orbital tooth triangular;terminal segment of G1 about a quarter length of subterminal
segment.....................................................................................5
5. Epibranchial tooth distinct on both sides, separated fromexternal orbital tooth by deep, broad U-shaped cleft; external
orbital tooth triangular (Fig. 4C); G1 with cone-shaped terminal
segment, about a quarter length of subterminal; distal segmentof G2 less than fifth length of basal segment (Fig. 5F–J)........
...................................................... A. terrapes (eastern Sabah)– Epibranchial tooth distinct on both sides, small, blunt, notseparated from external orbital tooth by cleft...........................
........................................... A. rhadamanthysi (eastern Sabah)Fig. 6. Live colours of Arachnothelphusa rhadamanthysi from
Gomantong limestone cave in Sabah, specimen not collected. A,
male, from outside of the cave; B, inside of cave. Photographs:
Keith Christenson.

Members of Arachnothelphusa occur in a wide varietyof habitats ranging from tree-holes to caves. The only
other species of Arachnothelphusa known from caves
is A. rhadamanthysi. Arachnothelphusa sarang inhabits
exclusively deep interior of cave systems of Bukit Sarang
in northern Sarawak. Arachnothelphusa rhadamanthysi on
the other hand, has been found in more exposed areas near
the cave entrance of Gomantong limestone cave in western
Sabah (Fig. 6). Both species, however, are not troglobitic
species as neither have their eyes reduced and the corneas
are still completely pigmented, and A. rhadamanthysi at least
has been found at cave entrances. In this respect, the habitsof the two species are the same as species of Stygothelphusa,
which are regarded as troglophilic taxa instead (Ng, 1991,
2013; Ng & Grinang, 2014). Another cavernicolous
gecarcinucid from Borneo, Balssiathelphusa phasma Ng &Guinot, 2014, from eastern Kalimantan in Indonesia, is also
regarded as troglophilic (Ng & Guinot, 2014). As such, theonly true stygobitic crabs in Borneo are the two species ofCerberusa Holthuis, 1979, from northern Sarawak (family
Potamidae) (Holthuis, 1979) and the monotypic Guaplax
Naruse, Ng & Guinot, 2008, from southern Kalimantan(family Hymenosomatidae) (Naruse et al., 2008).
Habitat. The habitat of A. sarang, new species, is a limestone
outcrop. Bukit Sarang in Bintulu is an isolated limestone

6

RAFFLES BULLETIN OF ZOOLOGY 2021
ACKNOWLEDGEMENTS

Naruse T, Ng PKL & Guinot D (2008) Two new genera andtwo new species of troglobitic false spider crabs (Crustacea:
Decapoda: Brachyura: Hymenosomatidae) from Indonesia,
with notes on Cancrocaeca Ng, 1991. Zootaxa, 1739: 21–40.
Ng PKL (1988) The freshwater crabs of Peninsular Malaysia andSingapore. Department of Zoology, National University ofSingapore, Shinglee Press, Singapore, viii + 156 pp., 63 figs.,
4 colour pls.
Ng PKL (1989) The identity of the cavernicolous freshwater crab
Potamon (Thelphusa) bidiense Lanchester, 1900 (Crustacea:
Decapoda: Brachyura: Gecarcinucidae) from Sarawak, Borneo,
with description of a new genus. Raffles Bulletin of Zoology,
37(1–2): 63–72.
Ng PKL (1991) Bornean freshwater crabs of the genus
Arachnothelphusa gen. nov. (Crustacea: Decapoda: Brachyura:
Gecarcinucidae). Zoologische Mededelingen, 65: 1–12.
Ng PKL (2013) Stygothelphusa cranbrooki, a new species of cavecrab from Gua Sireh, Sarawak, Malaysia (Crustacea: Decapoda:
Brachyura: Gecarcinucidae). Raffles Bulletin of Zoology,
Supplement 29: 91–97.
Ng PKL & Goh R (1987) Cavernicolous freshwater crabs (Crustacea,
Decapoda, Brachyura) from Sabah, Borneo. Stygologia, 3(4):313–330.
Ng PKL & Grinang J (2014) On a new species of troglobitic crabof the genus Stygothelphusa Ng, 1989, from Sarawak, Malaysia(Crustacea: Decapoda: Brachyura: Gecarcinucidae). Zootaxa,
3774(1): 90–96.
Ng PKL & Guinot D (2014) A new cavernicolous species ofcrab of the genus Balssiathelphusa Bott, 1969 (Crustacea,
Brachyura, Gecarcinucidae) from eastern Borneo. Zoosystema,36(3): 623–629.
Ng PKL & Ng PYC (2018) The freshwater crabs of Danum Valley
Conservation Area in Sabah, East Malaysia, with a descriptionof a new species of Thelphusula Bott, 1969 (Crustacea,
Brachyura, Gecarcinucidae, Potamidae, Sesarmidae). Zookeys,
760: 89–112.
Rathbun MJ (1904) Les crabes d’eau douce (Potamonidae).
Nouvelles Archives du Muséum d’Histoire Naturelle, Paris,
Series 4, 6: 225–312, pls. 9–18.

We thank Rob Stuebing for making the arrangements tomake collections at this site in Grand Perfect; and to Tan
Heok Hui for collecting the specimens used for the study.
The late Michael Türkay (SMF) kindly hosted the second
author in his visits to examine the type of A. kadamaiana.
We are also grateful to Keith Christenson and Tan Heok Huifor allowing us to use their photos of A. rhadamanthysi andA. sarang, respectively. We thank Jose Christopher Mendoza
and Célio Magalhães for their constructive comments ofthis manuscript. The first author thanks the Institute of
Biodiversity and Environmental Conservation, Universiti
Malaysia Sarawak, for laboratory space and technical support.
Research Permit No. NCCD.907.4.4 (JLD. 13)-307 was
granted by the Sarawak Forest Department. The researchis partly supported by Project No. GL(I01)/MPOB/03/2016.
LITERATURE CITED
Borradaile LA (1900) On a small collection of decapod crustaceansfrom freshwater in North Borneo. Proceedings of the ZoologicalSociety of London, 1900: 93–95.
Davie PJF, Guinot D & Ng PKL (2015) Anatomy and functional
morphology of Brachyura. In: Castro P, Davie PJF, Guinot
D, Schram FR & Von Vaupel Klein JC (eds.) Treatise on
zoology — anatomy, taxonomy, biology. The Crustacea, 9C–I:
Decapoda: Brachyura (part 1). Brill, Leiden. Pp. 11–163.
Grinang J, Pui YM & Ng PKL (2015) A new species of treehole dwelling freshwater crab of the genus Arachnothelphusa
Ng, 1991 (Crustacea: Decapoda: Brachyura: Gecarcinucidae)
from northern Sarawak, Malaysia, Borneo. Raffles Bulletin of
Zoology, 63: 454–460.
Holthuis LB (1979) Cavernicolous and terrestrial decapod crustacea
from northern Sarawak, Borneo. Zoologische Verhandelingen,
171: 1–47, pls. 1–8.
Man JG De (1899) Zoological Results of the Dutch Expedition toCentral Borneo. The Crustacea. Part II, Brachyura. Notes fromthe Leyden Museum, 21: 53–144, pls. 5–12.

7