Pilumnopeus indicus ( De Man, 1887 ), 2024

Patel, Krupal, Trivedi, Jigneshkumar, Mitra, Santanu & Ng, Peter K. L., 2024, The taxonomy of Heteropanope indica De Man, 1887 from the Indian Ocean, with a note on Pilumnopeus pearsei (Rathbun, 1932) (Crustacea: Decapoda: Brachyura: Pilumnidae), Zootaxa 5437 (3), pp. 384-396 : 386-393

publication ID	https://doi.org/10.11646/zootaxa.5437.3.4
publication LSID	lsid:zoobank.org:pub:9BBBD828-DC3A-4ADC-9C88-5488E7536554
DOI	https://doi.org/10.5281/zenodo.11049009
persistent identifier	https://treatment.plazi.org/id/03A6BA32-FF82-C202-FF6C-FF2E93C2F827
treatment provided by	Plazi (2024-04-17 09:06:23, last updated 2024-11-28 15:01:45)
scientific name	Pilumnopeus indicus ( De Man, 1887 )
status	comb. nov.

Treatment

Pilumnopeus indicus ( De Man, 1887) View in CoL comb. nov.

( Figs. 1–5 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 )

Heteropanope indica De Man, 1887: 53 View in CoL , pl. 3, figs. 1, 2.— Alcock 1898: 208.— Kemp 1915: 242.

Pilumnopeus indica — Balss 1933: 33.

Heteropanope (Pilumnopeus) indica View in CoL — Serène 1968: 87.

Benthopanope indica View in CoL — Davie 1989: 144 (list).— Ng & Davie 2002: 377 (list).— Ng et al. 2008: 140 (list).— Dev Roy & Nandi 2008: 204 (list).— Trivedi et al. 2018: 58 (list).

Material examined. Type material: Lectotype (herein selected), female ( CW 14.7 mm, CL 10.2 mm) ZSI.3209/6, Mergui Archipelago, coll. J. Anderson. Other material: 1 male (CW 22.4 mm, CL 15.8 mm), 1 ovig. female (CW 20.9 mm, CL 14.3 mm), LFSC.ZRC-70, Ekkakula mangroves (20°71’51”N 86°86’37”E), Gahirmatha National Park, Odisha state, India, coll. J. Trivedi, 15 August 2019 ; 2 juvs. (CW 4.3 mm CL 3.2 mm, CW 3.8 mm CL 2.6 mm), ZRC 2019.1092 View Materials , intertidal rocky area with algae, just outside School of Marine Sciences , Cochin University, Cochin India, Kerala, India, coll. students, February 2019 ; ZRC 2021.0683 View Materials , probably Chennai coast, India, coll. M. Prema, 2018 ; 1 young female (CW 8.5 mm CL 5.6 mm), ZRC 2018.0097 View Materials , Jeram Polychaete Reef, intertidal muddy shore and intermittent sabellariid reefs, lower shore, Jeram , Kuala Selangor, Peninsular Malaysia, 3º13’ 27”N 101º18’13”E, coll. J.J. Eeo, 6 October 2013 GoogleMaps ; 1 female (CW 16.8 mm CL 12.1 mm), ZRC 2021.0682 View Materials , 1 female (CW 18.1 mm CL 11.8 mm), 1 ovig. female (CW 1.4 mm CL 11.5 mm), ZRC 2017.1217 View Materials , Jeram Polychaete Reef , intertidal muddy shore and intermittent sabellariid reefs, lower shore, Jeram , Kuala Selangor, Peninsular Malaysia, 3º13’ 27”N 101º18’13”E, coll. J.J. Eeo, 14 December 2012 GoogleMaps .

Comparative material. Pilumnopeus serratifrons ( Kinahan, 1856) : 1 male ( CW 19.9 mm, CL 14.8 mm), 1 female ( CW 13.9 mm, CL 10.4 mm), ZRC 1995.0972, Cudgera Creek, Hastings Point, New South Wales, Australia, coll. P.J.F. Davie, 15 May 1988; 1 female ( CW 7.4 mm CL 5.6 mm), ZRC 2023.0378, near mouth of Brisbane River, Brisbane, Queensland, Australia, coll. Queensland University Zoology Department; 1 female ( CW 13.1 mm CL 9.1 mm), ZRC 2008.0114, under boulders, low tide, near lighthouse, Lowly Point, Whyalla, South Australia, coll. S. & B. Ahyong, 9 May 2005. Pilumnopeus pearsei ( Rathbun, 1932) : Lectotype: male ( CW 9.2 mm CL 7.2 mm), USNM 62910a, Misaki, Japan, coll. A.S. Pearse, 5 August 1929; 1 paralectotype ovigerous female ( CW 8.2 mm CL 6.1 mm), USNM 62910b, same data as lectotype; 2 males ( CW 10.3 mm CL 8.2 mm, 10.5 X 8.0 mm), ZRC 2023.0377, Korea, coll. S.Y. Hong, ca. 2002. Pilumnopeus granulatus Balss, 1933: 2 males ( CW 8.3 mm CL 5.8 mm, CW 15.0 mm CL 11.2 mm), 1 ovigerous female ( CW 16.6 mm CL 11.6 mm), ZRC 2023.0379, Korea, coll. S.Y. Hong, ca. 2002. Pilumnopeus makianus (Rathbun, 1931) : 2 males (larger CW 16.0 mm CL 11.5 mm), 1 female (not measured), ZRC 1997.677, San-Tao-Lun, Yunlin County, Taiwan, coll. 1996; 1 male (not measured), ZRC 2016.0716, mudflat, Youkaku Bay, Amasuka, Kumamoto Prefecture, Japan, coll. Amasuka Marine Laboratory, no date. Pilumnopeus marginatus (Stimpson, 1858) : 1 female (not measured), ZRC 2023.0380, Ohura River, Okinawa Island, Ryukyus, Japan, coll. M. Irei, 16 November 1990; 1 female (not measured), ZRC 2013.0160, Naha City, Okinawa Island, Ryukyus, Japan, coll. T. Maenosono, 9 April 2007. Pilumnopeus vauquelini (Audouin, 1826) : 1 male (not measured), ZRC 2013.1795, around Qeslim Island, west of Homorzgan, Dargahan, Iran, 14–15 fathoms, in shrimp trawl, coll. M. Safaei, 2 February 2013.

Description (based on the morphology of male (CW 22.4 mm CL 15.8 mm): Carapace transversely hexagonal, broader than long (1.4–1.5 times) ( Figs. 1A View FIGURE 1 , 2A View FIGURE 2 , 3A View FIGURE 3 , 4A View FIGURE 4 ). Front distinctly bilobed, margin of each almost straight in dorsal view, separated by deep triangular notch, bearing small outer angle; inner supraorbital tooth small but distinct, supraorbital margin with 2 fissures on external half ( Figs. 1A View FIGURE 1 , 2A View FIGURE 2 , 3A View FIGURE 3 , 4A View FIGURE 4 ). Dorsal surface covered with scattered plumose setae barely visible with naked eyes. Frontal region with slightly arcuate, transverse row of small granules; epigastric and protogastric region with 5 transverse, minutely granulated low ridges, pubescent ( Figs. 1A View FIGURE 1 , 2A View FIGURE 2 , 3A View FIGURE 3 , 4A View FIGURE 4 ). Anterolateral margin with 3 teeth behind exorbital angle; first anterolateral tooth blunt, second and third teeth acute but not spine-tipped, third and fourth teeth subequal in size, or with third tooth slightly smaller; fourth tooth directed almost laterally or obliquely laterally ( Figs. 1A View FIGURE 1 , 2A View FIGURE 2 , 3A View FIGURE 3 , 4A View FIGURE 4 ). Epistome nearly smooth, median lobe broadly triangular, protruding anteriorly.

Third maxilliped with merus broader than long, much shorter than ischium, anterior and outer lateral margins slightly concave; ischium with oblique longitudinal depression, exopod not reaching anterior margin of merus, large rounded triangular subdistal tooth on inner margin, internal edge adjacent to merus and ischium granulated; flagellum long ( Figs. 1E View FIGURE 1 , 3E View FIGURE 3 ).

Chelipeds unequal; surface of larger chela gently rugose to almost smooth; smaller chela covered with scattered small granules and scattered short setae; carpus with blunt, inner subdistal tooth, inner distal margin of carpus granulated; fingers shorter than palm, cutting edges of fingers toothed, dentition stronger in larger chela ( Figs. 1C, D View FIGURE 1 , 2C, D View FIGURE 2 , 3C, D View FIGURE 3 , 4D, E View FIGURE 4 ).

Ambulatory legs relatively short; coxa, merus, carpus and propodus unarmed; covered with scattered long and short setae that partially obscure surface; dactylus terminating in acute chitinous tip ( Figs. 1A, B View FIGURE 1 , 2A, B View FIGURE 2 , 3A, B View FIGURE 3 ).

Thoracic sternites 1 and 2 completely fused; sternites 2 and 3 separated by broad V-shaped suture, sternites 3 and 4 relatively long, transversely narrow, distance between tip of sternopleonal cavity and median point of suture between thoracic sternites 3 and 4 long, longer than distance between the sutures of sternites 3 and 4, and sternites 2 and 3; sternite 8 visible adjacent to male pleonal somite 3 ( Figs. 1F View FIGURE 1 , 2F View FIGURE 2 , 3F View FIGURE 3 ). Pleon with 6 free somites and telson, covered with fine setae; telson triangular with rounded tip ( Fig. 2B, G View FIGURE 2 ).

G1 slender, sinuous; distal part distinctly recurved from ventral view, with several large subdistal spines, stout setae along the inside edge near tip ( Fig. 4A, B View FIGURE 4 ). G2 short, sigmoid, tip margin armed with spinules ( Fig. 4C View FIGURE 4 ).

Ecological observations. Pilumnopeus indicus ( De Man, 1887) comb. nov. inhabits the intertidal zone in muddy or mangrove habitats. Individuals of the species are mostly found under dead logs or rock boulders in India; and the Malaysian specimens were from an unstable muddy polychaete reef subjected to strong tides.

Distribution. The species was originally described from the Mergui Archipelago ( De Man 1887) and is now known from various localities in India (Deb 1995; Trivedi et al. 2018, present study) and the western coast of Peninsular Malaysia (present record). Records of the species from East Asia, including Japan (e.g., Rathbun 1932; T. Sakai 1939, 1965, 1976; Miyake 1983; Wada 1995), Korea (e.g., Kamita 1941; Kim 1973; Kim & Chang 1985; Ko & Lee 2012), as well as Taiwan and mainland China (e.g., Dai et al. 1986; Dai & Yang 1991; Jeng et al. 1997; Ho et al. 2000; Ng et al. 2001, 1017) are here referred to P. pearsei (see discussion later).

Remarks. De Man (1887) described Heteropanope indica from one male and one female collected from the Mergui Archipelago and figured the overall dorsal habitus of the male and its right chela ( De Man 1887: pl. 3 figs. 1, 2). As no type was designated, both his specimens are syntypes. Only the female specimen could be found in ZSI, the whereabouts of the male is not known. De Man’s (1887) types from the John Anderson expedition are known to be also deposited in the Natural History Museum, London, but the male could not be found there. Hence, the female ZSI specimen on hand is designated as the lectotype of H. indica . In the present study, the lectotype and fresh specimens of B. indica are redescribed and illustrated. Balss (1933) transferred H. indica to Pilumnopeus A. Milne-Edwards, 1873 , in his reappraisal of pilumnid genera. On comparing the Japanese material identified as Pilumnopeus indicus with the type of H. pearsei, T. Sakai (1965: 160) argued that the two species appeared similar, and hence the latter was considered a junior synonym. This classification has since been followed by most later workers, including subsequent workers who reported it from Japan, Korea, China and Taiwan (T. Sakai, 1939, 1965, 1976; Kim 1973; Miyake 1983; Dai et al. 1986; Dai & Yang 1991; Jeng et al. 1997; Ho et al. 2000; Ko & Lee 2012). Davie (1989) did not treat or discuss H. pearsei . As for H. pearsei, Ng et al. (2001: 30) made a brief note on the inclusion of which as “ B. indica ” among the fauna of Taiwan, stating B. indica and Heteropanope pearsei represent distinct species (repeated by Ng et al. 2017). Both species, listed under Benthopanope , have been kept distinct by Ng et al. (2008).

The last author of the present study has examined the types of H. pearsei and it is a Pilumnopeus species as indicated by Ng et al. (2008) and as defined by Davie (1989). In the type lot (USNM 62910), the label indicates there are “2 cotypes and 10 paratypes ”. Rathbun (1932: 35–36) described the species from one “Type” male measuring “9.4 X 7.0 mm” from Misaki, Japan, with the catalogue number of USNM 62910, and this is considered to be the male examined here, differing only slightly in measurements. This specimen, following Article 73.1.2 and Recommendation 73F of the current zoological code ( ICZN 1999), should be regarded as the lectotype of the species as Rathbun (1932) did not state if she had more specimens in the original paper. There are in fact 11 more specimens as the present data shows, all of which are in the same container with the same data and under the same catalogue number. They should now be regarded as paralectotypes ( ICZN 1999: Articles 72.4.1, 72.4.1.1).

Comparisons show that H. indica De Man, 1887 , and H. pearsei Rathbun, 1932 , are distinct species, and both belong to Pilumnopeus . Pilumnopeus indicus differs in having the third and fourth anterolateral teeth clearly dentiform and subequal in size ( Figs. 1A View FIGURE 1 , 2A View FIGURE 2 , 3A View FIGURE 3 , 4A View FIGURE 4 ) (versus fourth tooth much smaller and lower than the third tooth in P. pearsei ; Fig. 6A–C; T View FIGURE 6 . Sakai 1976: pl. 178 fig. 1); the fourth anterolateral tooth is directed obliquely laterally to almost laterally ( Figs. 1A View FIGURE 1 , 2A View FIGURE 2 , 3A View FIGURE 3 , 4A View FIGURE 4 ) (versus fourth tooth directed more anteriorly; Fig. 6A–C; T View FIGURE 6 . Sakai 1976: pl. 178 fig. 1); the median lobe of the posterior margin of epistome is low ( Fig. 2F View FIGURE 2 ) (versus median lobe triangular and pronounced; Fig. 6D View FIGURE 6 ); the tooth at the inner angle of the carpus of the cheliped is prominent and sharp ( Figs. 1A View FIGURE 1 , 2A View FIGURE 2 , 3A View FIGURE 3 , 4A, C View FIGURE 4 ) (versus lower and generally more rounded; Fig. 6A–C; T View FIGURE 6 . Sakai 1976: pl. 178 fig. 1); the lateral margin of the male pleonal somite 2 is gently convex ( Fig. 2E View FIGURE 2 ) (versus margin distinctly convex; Fig. 6H View FIGURE 6 ); and most significantly the G1 is relatively more longer, with the distal part strongly recurved with the tip overlapping with the main stem ( Fig. 5A, B View FIGURE 5 ) (versus G1 relatively shorter, with the distal part more gently curved; Fig. 7A–C View FIGURE 7 ; Takeda & Miyake 1969: fig. 12a, b; Dai et al. 1986: text-fig. 182(1); Dai & Yang 1991: text-fig. 182(1)).

With regard to distribution, the East Asian records of “ Pilumnopeus indica ” (T. Sakai 1939: 542, pl. 62, fig. 4; Kamita 1941: 133, fig. 72; T. Sakai 1965: 159, pl. 79, fig. 4; Kim 1970: 16; T. Sakai 1976: 500, pl. 178, fig. 2; Dai et al. 1986: 348, text-fig. 182, pl. 50(4); Dai & Yang 1991: 374, text-fig. 182, pl. 50(4); Wada 1995: 403, pl. 112, fig. 4; Muraoka 1998: 45); “ Pilumnopeus indicus ” ( Takeda & Miyake 1969: 125, fig. 12a, b; Miyake 1983: 138, pl. 46, fig. 5; Jeng et al. 1997: 118; Kim & Chang 1985: 54); “ Heteropanope (Pilumnopeus) indica ” ( Kim 1973: 400, 634, fig. 158, pl. 84, fig. 120a-d.); and “ Benthopanope indica ” ( Ho et al. 2000: 116; Ng et al. 2001: 30; K. Sakai 2004: no page number; Ko & Lee 2012: 24, pl. 5; Ng et al. 2017: 62) should now all be referred to P. pearsei . The G1 structure of the Japanese lectotype of P. pearsei ( Fig. 7A–C View FIGURE 7 ) generally agrees with those specimens from China ( Dai et al. 1986; Dai & Yang 1991).

Pilumnopeus indicus is similar to P. convexus , however, they can be differentiated on the basis of the following characters: front comparatively less projecting in P. indicus ( Figs. 1A View FIGURE 1 , 2A View FIGURE 2 , 3A View FIGURE 3 , 4A View FIGURE 4 ) (versus front comparatively more projecting in P. convexus ; Ghory et al. 2013: figs. 1A, 2A, B); dorsal surface with regions well defined in P. indicus ( Figs. 1A View FIGURE 1 , 2A View FIGURE 2 , 3A View FIGURE 3 , 4A View FIGURE 4 ) (versus dorsal surface with regions not well defined in P. convexus ; Ghory et al. 2013: figs. 1A, 2A, B); distal region of G1 with less numerous spines in P. indicus ( Fig. 4B View FIGURE 4 ) (versus distal region of G1 with more numerous spines in P. convexus ; Ghory et al. 2013: figs. 4G, 5F); the curved distal part of G1 is more elongated in P. indicus ( Fig. 4B View FIGURE 4 ) (versus the curved distal part of G1 less elongated; Ghory et al. 2013: fig. 4G); no spines present on the outer boarder of the distal part of G1 ( Fig. 4B View FIGURE 4 ) (versus numerous spines present on the outer boarder of the distal part of G1; Ghory et al. 2013: fig. 4G); distal part of G1 inner margin with long and more numerous spines ( Fig. 4B View FIGURE 4 ) (versus distal part of G1 inner margin with short and less numerous spines; Ghory et al. 2013: fig. 4G); and G2 is less prominently bilobed in P. indicus ( Fig. 4C View FIGURE 4 ) (versus G2 more prominently bilobed in P. convexus ; Ghory et al. 2013: fig. 4H). Ghory et al. (2013) and Wong et al. (2020) have noted that the record of “ P. indica ” from South Africa by Barnard (1955) is almost certainly P. convexus , and that Pilumnopeus salomonensis Ward, 1942 , from the Chagos Archipelago is a junior synonym of this species (see also Takeda & Miyake 1969: 127; Davie 1989: 143).

Pilumnopeus indicus is also similar to P. serratifrons , but it can be differentiated from the latter in the following characters: carapace comparatively broader than long (1.4–1.5 times) in P. indicus ( Figs. 1A View FIGURE 1 , 2A View FIGURE 2 , 3A View FIGURE 3 , 4A View FIGURE 4 ) (versus carapace comparatively less broader than long (1.3–1.4 times) in P. serratifrons ; Davie 1989: fig. 6); dorsal surface with five minutely granulated, pubescent, elevated lines on each side in P. indicus ( Figs. 1A View FIGURE 1 , 2A View FIGURE 2 , 3A View FIGURE 3 , 4A View FIGURE 4 ) (versus dorsal surface with small, rounded granules laterally, behind the epibranchial teeth and posterolaterally in P. serratifrons ; Davie 1989: fig. 6); front comparatively less projecting in P. indicus ( Figs. 1A View FIGURE 1 , 2A, F View FIGURE 2 , 3A View FIGURE 3 , 4A View FIGURE 4 ) (versus front comparatively more projecting in P. serratifrons ; Davie 1989: fig. 6) and distal part of the G1 is comparatively less curved in P. indicus ( Fig. 4A, B View FIGURE 4 ) (versus distal part of G1 comparatively more curved in P. serratifrons ; Davie 1989: fig. 5F).

Pilumnopeus indicus resembles P. vauquelini but can be differentiated on the basis of the following characters: carapace comparatively more broader than long (1.4–1.5 times) in P. indicus ( Figs. 1A View FIGURE 1 , 2A View FIGURE 2 , 3A View FIGURE 3 , 4A View FIGURE 4 ) (versus carapace comparatively squarish (1.35 times) in P. vauquelini ; Audouin 1826: pl. 5 fig. 3; Guinot & Cleva 2009: 98, pl. 5); fingers of chelae not bent downwards in P. indicus ( Figs. 1C, D View FIGURE 1 , 2C, D View FIGURE 2 , 3 C, D View FIGURE 3 , 4C, D View FIGURE 4 ) (versus fingers of chelae sharply bent downwards, forming sharp angle with palm in P. vauquelini ; De Man 1889: pl. 9, fig. 5); and the tip of G1 is recurved to form a distinct hook-like structure in P. indicus ( Fig. 4A, B View FIGURE 4 ) (versus the tip is more strongly curved in P. vauquelini ; Audouin 1826: pl. 5 fig. 3; Guinot & Cleva 2009: 98, pl. 5).

References

Alcock, A. (1898) Materials for a carcinological fauna of India. No. 3. The Brachyura Cyclometopa. Part I. The family Xanthidae. Journal of the Asiatic Society of Bengal, 67, 67 - 233.

Balss, H. (1933) Beitrage zur Kenntnis der Gattung Pilumnus (Crustacea, Decapoda) und verwandter Gattungen. Capita Zoologica, 4, 1 - 47.

Barnard, K. H. (1955) Additions to the fauna-list of South African Crustacea and Pycnogonida. Annals of the South African Museum, 43, 1 - 107.

Dai, A. - Y., Yang, S. - L., Song, Y. - Z. & Chen, G. - X. (1986) Crabs of the China Seas. China Ocean Press, Beijing, 11 + 642 pp.

Dai, A. & Yang, S. (1991) Crabs of the China Seas. China Ocean Press, Beijing and Springer-Verlag, Berlin, Heidelberg, New York, Tokyo, 608 pp.

Davie, P. J. F. (1989) A re-appraisal of Heteropanope Stimpson, and Pilumnopeus A. Milne Edwards (Crustacea: Decapoda: Pilumnidae) with descriptions of new species and new genera. Memoirs of the Queensland Museum, 27, 129 - 156.

De Man, J. G. (1887) Report on the podophthalmous Crustacea of the Mergui Archipelago, collected for the Trustees of the Indian Museum, Calcutta, by Dr. John Anderson F. R. S., Superintendent of the Museum. Journal of the Linnean Society, Zoology, 22, 1 - 305. https: // doi. org / 10.1111 / j. 1096 - 3642.1887. tb 00027. x

De Man, J. G. (1889) Ueber einige neue oder seltene indopacifische Brachyuren. Zoologische Jahrb ¸ cher, Abteilung f ¸ r Systematik, Geographie und Biologie der Thiere, Jena, 4 (2), 409 - 452, pls. 9 + 10. https: // doi. org / 10.5962 / bhl. part. 18727

Dev Roy, M. K. & Nandi, N. C. (2008) Checklist and distribution of Brachyuran crabs of West Bengal, India. Journal of Environment and Sociobiology, 5, 191 - 214.

Ghory, F., Ng, P. K. L. & Kazmi, Q. B. (2013) On the identities of Pilumnopeus convexus Maccagno, 1936, and P. salomonensis Ward, 1942, from the Indian Ocean, with a note on P. riui Takeda, 2001 (Decapoda, Brachyura, Pilumnidae). Crustaceana, 86, 301 - 312. https: // doi. org / 10.1163 / 15685403 - 00003180

Guinot, D. & Cleva, R. (2009) Publication preliminaire des Nouvelles explications des planches de Crustaces Decapodes de la Description de l'Egypte (planches 1 a 10) dessinees sous la direction de Jules-Cesar Savigny et commentees sommairement a l'origine par Victor Audouin, et explication des especes inedites de Crustaces figurant dans l' Atlas d'Histoire naturelle de Savigny (volume 4, planches 52, 54, 61 a 66), accompagnees de precisions et commentaires scientifiques et historiques. In: Collection nouvelle description de l'Egypte. Institut d'Orient, Paris, pp. 1 - 195.

Ho, P. - H., Yu, H. - P. & Ng, P. K. L. (2000) New records of Eriphiiidae, Pilumnidae and Xanthidae (Crustacea: Decapoda: Brachyura) from Taiwan. Raffles Bulletin of Zoology, 48, 111 - 122.

ICZN [International Commission on Zoological Nomenclature] (1999) International Code of Zoological Nomenclature. International Commission of Zoological Nomenclature. Fourth Edition. Adopted by the XXI General Assembly of the International Union of Biological Sciences. International Trust for Zoological Nomenclature, in association with the British Museum (Natural History), London, 338 pp.

Jeng, M. - S., Chan, R. - G., Fung, H. - R. & Tzeng, C. - S. (1997) Northeast Coast Scenic Area. Investigations into ecological resources and monitoring (III). Ministry of Transport and Tourism, Taipei, 194 pp.

Kamita, T. (1941) Studies of the Decapod Crustaceans of Chosen. Pt. I. Crabs. The Fisheries Society of Chosen, Keijo, 289 pp., 147 figs., 2 pls., 1 map.

Kemp, S. (1915) Crustacea Decapoda. In: Fauna of the Chilka Lake. No. 3. Memoirs of the Indian Museum, Calcutta, India, 5, 199 - 325.

Kim, H. S. (1970) A checklist of the Anomura and Brachyura (Crustacea, Decapoda) of Korea. Seoul National University Journal, Biology and Agriculture Series, B, 21, 1 - 34, pls. 1 - 5.

Kim, H. S. (1973) A Catalogue of Anomura and Brachyura from Korea. In: Illustrated Encyclopedia of Fauna and Flora of Korea. Samhwa Publishing Company, Seoul, pp. 1 - 694.

Kim, H. S. & Chang, C. Y. (1985) The brachyuran crabs of Cheju Island, Korea (Crustacea: Decapoda). Korean Journal of Systematic Zoology, 1, 41 - 60.

Kinahan, J. R. (1856) Remarks on the Habits and Distribution of Marine Crustacea on the eastern shores of Port Phillip, Victoria, Australia; with Descriptions of undescribed Species and Genera. Journal of the Royal Dublin Society, 1 (3), 111 - 134, pls. 3 + 4.

Ko, H. S. & Lee, S. H. (2012) Invertebrate fauna of Korea. Crabs and Zoeas II. Arthropoda: Malacostraca: Decapoda: Brachyura: Eriphioidea, Pilumnoidea, Xanthoidea. National Institute of Biological Resources 21 & 22. National Institute of Biological Resources, Incheon, pp. 93.

Miyake, S. (1983) Japanese Crustacean Decapods and Stomatopods in colour. Hoikusha Publishing Corporation Limited, Osaka, 174 pp.

Muraoka, K. (1998) Catalogue of the brachyuran and anomuran crabs donated by Prof. Dr. Tune Sakai to the Kanagawa Prefectural Museum. Catalogue of the collection in the Kanagawa Prefectural Museum of Natural History, Odawara, 11, 1 - 67, 16 pls.

Ng, P. K. L., Wang, C. - H., Ho, P. - H. & Shih, H. - T. (2001) An annotated checklist of brachyuran crabs from Taiwan (Crustacea: Decapoda). National Taiwan Museum Special Publication Series, No. 11, 1 - 86, 8 colour pls.

Ng, P. K. L. & Davie, P. J. F. (2002) A checklist of the Brachyuran Crabs of Phuket and Western Thailand. Phuket Marine Biological Center Special Publication, 23, 369 - 384.

Ng, P. K. L., Guinot, D. & Davie, P. J. F. (2008) Systema Brachyurorum: Part I. An annotated checklist of extant brachyuran crabs of the world. Raffles Bulletin of Zoology, Supplement 17, 1 - 286.

Ng, P. K. L., Shih, H. - T., Ho, P. - H. & Wang, C. - H. (2017) An updated annotated checklist of brachyuran crabs from Taiwan (Crustacea: Decapoda). Journal of the National Taiwan Museum, 70 (3 & 4), 1 - 185.

Rathbun, M. J. (1932) Preliminary descriptions of new species of Japanese crabs. Proceedings of the biological Society of Washington, 45, 28 - 38.

Sakai, T. (1939) n. k. In: Studies on the crabs of Japan. IV. Brachygnatha, Brachyrhyncha. Yokendo Co., Ltd., Tokyo, pp. 365 - 741 + 1 - 23 (index), pls. 42 - 111.

Sakai, T. (1965) The crabs of Sagami Bay, collected by His Majesty the Emperor of Japan. Biological Laboratory, Imperial Household, Tokyo, 206 pp., 27 text-figs., 100 pls.

Sakai, T. (1976) Crabs of Japan and the Adjacent Seas. 3 Vols. Kodansha Ltd., Tokyo, xxix + 773 pp. (English text), 461 pp. (Japanese text), 16 pp., 251 pls. (plates volume).

Sakai, K. (2004) Crabs of Japan. World Biodiversity Database, CD-Rom Series.

Serene, R. (1968) The Brachyura of the Indo Pacific Region. In: Prodromus for a Check List of the Non-planctonic Marine Fauna of South East Asia. Special Publication of the Singapore National Academy of Science, No. 1, 33 - 120.

Takeda, M. & Miyake, S. (1969) Pilumnid crabs of the family Xanthidae from the West Pacific. II. Twenty-one species of four genera, with descriptions of four new species. OHMU, Occasional Papers of the Zoological Laboratory, Faculty of Agriculture, Kyushu University, Fukuoka, Japan, 2, 93 - 156.

Trivedi, J. N., Trivedi, D. J., Vachhrajani, K. D. & Ng, P. K. L. (2018) An annotated checklist of the marine brachyuran crabs (Crustacea: Decapoda: Brachyura) of India. Zootaxa, 4502 (1), 1 - 83. https: // doi. org / 10.11646 / zootaxa. 4502.1.1

Wada, K. (1995) Brachyura. In: Guide to seashore animals of Japan with color pictures and keys. Hoikusha, Osaka, pp. 379 - 418.

Ward, M. (1942) Notes on the Crustacea of the Desjardins Museum, Mauritius Institute, with descriptions of new genera and species. Bulletin of the Mauritius Institute, 2 (2), 49 - 113, pls. 5 + 6.

Wong, K. J. H., Tsang, L. M. & Ng, P. K. L. (2020) Journey from the West: first record of the Indian Ocean pilumnid crab Pilumnopeus convexus (Maccagno, 1936) (Decapoda: Brachyura: Pilumnoidea) in Hong Kong. Journal of Crustacean Biology, 40 (5), 563 - 573. https: // doi. org / 10.1093 / jcbiol / ruaa 056

Figures

FIGURE 1. Pilumnopeus indicus (De Man, 1887) comb. nov., lectotype female (CW 14.7 mm CL 10.2 mm), ZSI.3209/6, Mergui Archipelago. A. overall dorsal habitus; B. overall ventral view; C. right chela (outer view); D. left chela (outer view); E. left third maxilliped; F. male pleonal somites 1–3, thoracic sternum and coxa of last ambulatory leg, showing small part of sternite 8 adjacent to pleonal somites 2 and 3. Scale bars: A–D = 5.0 mm, E, F = 2.0 mm.

FIGURE 2. Pilumnopeus indicus (De Man, 1887) comb. nov., male (CW 22.4 mm CL 15.8 mm), LFSC.ZRC-70, Odisha, India. A. overall dorsal habitus; B. overall ventral view; C. right chela (outer view); D. left chela (outer view); E. pleonal somites 1–3, thoracic sternum and coxa of last ambulatory leg, showing small part of sternite 8 adjacent to pleonal somites 2 and 3; F. frontal view of cephalothorax; G. thoracic sternum and pleon. Scale bars: A–D, F = 5.0 mm, E, G = 2.0 mm.

FIGURE 3. Pilumnopeus indicus (De Man, 1887) comb. nov., ovigerous female (CW 20.9 mm CL 14.3 mm), LFSC.ZRC-70, Odisha, India. A. overall dorsal habitus; B. overall ventral view; C. right chela (outer view); D. left chela (outer view); E. left third maxilliped; F. female pleonal somites 1–3, thoracic sternum and coxa of last ambulatory leg, showing small part of sternite 8 adjacent to pleonal somites 2 and 3. Scale bars: A–D = 5.0 mm, E, F = 2.0 mm.

FIGURE 4. Pilumnopeus indicus (De Man, 1887) comb. nov., female (CW 18.1 mm CL 11.8 mm), ZRC 2017.1217, Peninsular Malaysia, A. overall dorsal habitus; B. dorsal view of carapace; C. frontal view of cephalothorax; D. right chela (outer view); E. left chela (outer view). Scale bars: A–D = 5.0 mm, E, F = 2.0 mm.

FIGURE 5. Pilumnopeus indicus (De Man, 1887) comb. nov., male (CW 22.4 mm CL 15.8 mm), LFSC.ZRC-70, Odisha, India. A. left G1 (dorsal view); B. distal part of left G1 (dorsal view); C. left G2. Scale bars: A = 1.0 mm; B, C = 0.5 mm.

FIGURE 6. Pilumnopeus pearsei Rathbun, 1932. A, D–H, topotype male (CW 9.2 mm CL 7.2 mm), USNM 62910, Korea; B, male (CW 10.5 mm CL 8.0 mm), ZRC 2023.0377, Korea; C, topotype ovigerous female (CW 8.2 mm CL 6.1 mm), USNM 62910, Korea.A–C. overall dorsal habitus; D. frontal view of cephalothorax; E. left chela (outer view); F, right third maxilliped; G. thoracic sternites 1–6 and pleonal somites 6 and telson; H. pleonal somites 1–4, thoracic sternum and coxa of last ambulatory leg, showing small part of sternite 8 adjacent to male pleonal somites 2 and 3.

FIGURE 7. Pilumnopeus pearsei Rathbun, 1932, topotype male (CW 9.2 mm CL 7.2 mm), USNM 62910, Korea. A. left G1 (ventral view); B. distal part of left G1 (ventral view); C. distal part of left G1 (dorsal view); D. left G2; E. distal part of left G2. Scale bars: A = 0.5 mm; B, C = 0.2 mm; D = 0.25 mm; E = 0.1 mm.

Abbreviations

ZRC	Zoological Reference Collection, National University of Singapore
USNM	Smithsonian Institution, National Museum of Natural History
T	Tavera, Department of Geology and Geophysics