Family LEUCOSIIDAE Samouelle, 1819

Museums

Regional Maps

• Nursioida Alcock, A. 1896. Materials for a Carcinological Fauna of India. No. 2. The Brachyura Oxystoma. Journal of the Asiatic Society of Bengal 65(Pt 2 No. 2): 134-296 pls 6-8 [166].

 

Taxonomic Decision for Synonymy

• Manning, R.B. & Holthuis, L.B. 1981. West African Brachyuran Crabs (Crustacea: Decapoda). Smithsonian Contributions to Zoology No. 306: i-xii, 1-379 figs 1-88, 2 appendices [57]

 

Introduction

The best known leucosiids are the 'pebble crabs' of the genus Leucosia and related genera of the Leucosiinae. Leucosiids are common in the soft sand to sandy-mud bottoms of Australia's coastal waters although, because of their burrowing habit, they are relatively rarely encountered, unless by dredging or trawling. They can be varied in shape but more typically are globular and round to elongate oval, with very small eyes and a more or less pointed snout. This snout is the result of a forward elongation and narrowing of the mouth frame, which carries both the inhalant and exhalant respiratory channels to its tip, and allows the crab to pump water to the gills whilst remaining almost entirely buried in the substrate.

Many genera are clearly polyphyletic and need revision. The best general introduction to the group is that of Sakai (1976). The most significant works on the Australian fauna include: Hale (1927), Tyndale-Biscoe & George (1962), Campbell & Stephenson (1970), Campbell (1971), George & Clark (1976), Arnold & George (1987), and Ovaere (1988). Galil (2001a,b,c; 2003a,b; 2005a,b; 2006; 2009) has recently been actively revising a number of genera in this family. The subfamily Philyrinae Rathbun, 1937, has recently been merged back under the Ebaliinae Stimpson, 1871 (see Ng et al. 2008 for explanation).

 

Excluded Taxa

Misidentifications

LEUCOSIIDAE: Leucosia perlata De Haan, 1841 — Galil, B.S. 2003. Contribution to the knowledge of Leucosiidae I. The identity of Leucosia craniolaris (Linnaeus, 1758), and the redefinition of the genus Leucosia Weber, 1795 (Crustacea: Brachyura). Zoologische Mededelingen (Leiden) 77(8): 181-191, figs 1-2

 

Diagnosis

Carapace shape varied, from subcircular to ovoid, pyriform or pentagonal; regions often not defined; smooth or armed with spines or lobes. Eyes and orbits very small. Frontal region narrowed and more or less produced anteriorly. Antennules folding more or less obliquely. Antennae small, sometimes obsolete. Third maxillipeds elongate, completely closing buccal cavern; palp arises from groove near inner edge of dorsal surface, completely hidden when third maxillipeds closed; exopod broad. Afferent branchial canals opening at bases of third maxillipeds, running along sides of buccal cavity, and covered by exopods of third maxilliped. Efferent branchial channels covered by pair of lamellar processes from first maxilliped. Chelipeds symmetrical, more or less robust and elongate. Walking legs with dactyli simple, not lanceolate or natatorial. Abdomen with some segments fused in both sexes. Female genital openings sternal; male openings coxal or sternal. Male second gonopod short.

 

General References

Arnold, P.W. & George, R.W. 1987. Recognition of Leucosia whitei Bell and Leucosia cheverti Haswell (Decapoda, Brachyura, Leucosiidae). Crustaceana 53(2): 209-214

Campbell, B.M. 1971. New records and new species of crabs (Crustacea: Brachyura) trawled off southern Queensland: Dromiacea, Homolidea, Gymnopleura, Corystoidea, and Oxystomata. Memoirs of the Queensland Museum 16(1): 27-48 figs 1-4 pls 2-3

Campbell, B.M. & Stephenson, W. 1970. The sublittoral Brachyura (Crustacea: Decapoda) of Moreton Bay. Memoirs of the Queensland Museum 15(4): 235-302 figs 1-49 pl. 22 1 table

Galil, B.S. 2001. A new genus and species of leucosiid crab (Crustacea, Decapoda, Brachyura) from the Indo-Pacific Ocean. Zoosystematica Rossica 23(1): 65-75

Galil, B.S. 2001. A revision of Myra Leach, 1817 (Crustacea: Decapoda: Leucosioidea). Zoologische Mededelingen (Leiden) 75(24): 409-446

Galil, B.S. 2001. A revision of the genus Arcania Leach, 1817 (Crustacea: Decapoda: Leucosioidea). Zoologische Mededelingen (Leiden) 75(11): 169-206

Galil, B.S. 2003. Contribution to the knowledge of Leucosiidae I. The identity of Leucosia craniolaris (Linnaeus, 1758), and the redefinition of the genus Leucosia Weber, 1795 (Crustacea: Brachyura). Zoologische Mededelingen (Leiden) 77(8): 181-191, figs 1-2

Galil, B.S. 2003. Contribution to the knowledge of Leucosiidae II. Euclosia gen. nov. (Crustacea: Brachyura). Zoologische Mededelingen (Leiden) 77(20): 331-347

Galil, B. S. 2003. Four new genera of leucosiid crabs (Crustacea: Brachyura: Leucosiidae) for three new species and nine previously in the genus Randallia Stimpson, 1857, with a redescription of the type species, R. ornata. Proceedings of the Biological Society of Washington 116(2): 395-422

Galil, B.S. 2005. Contributions to the knowledge of Leucosiidae III. Urnalana gen. nov. (Crustacea: Brachyura). Zoologische Mededelingen (Leiden) 79: 9-40

Galil, B.S. 2005. Contributions to the knowledge of Leucosiidae IV. Seulocia gen. nov. (Crustacea: Brachyura). Zoologische Mededelingen (Leiden) 79-2(3): 41-59

Galil, B.S. 2006. Contributions to the knowledge of Leucosiidae V. Coleusia gen. nov. (Crustacea: Brachyura). Zoologische Mededelingen (Leiden) 80: 57-69

Galil, B. S. 2009. An examination of the genus Philyra Leach, 1817 (Crustacea, Decapoda, Leucosiidae) with descriptions of seven new genera and six new species. Zoosystema 31(2): 279-320

George, R.W. & Clark, M. 1976. Two new species of pebble crab (Oxystomata: Leucosiidae) from Western Australia. Records of the Western Australian Museum 4(3): 303-309

Hale, H.M. 1927. The Crustaceans of South Australia. Eumalacostraca. Adelaide : Government Printer Vol. 1 201 pp., 202 figs.

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. The Raffles Bulletin of Zoology 17: 1-286 [Date published 31 January 2008]

Ovaere, A.A. 1988. A new species of the genus Leucosia from Australia and Papua New Guinea (Crustacea, Brachyura). Bulletin de l'Institut Royal des Sciences Naturelles de Belgique 58: 95-98

Sakai, T. 1976. Crabs of Japan and the Adjacent Seas. Tokyo : Kodansha 3 vols xxix 773 pp. [English vol.]; 1–16, 251 pls [Plates vol.]; 461 pp. [Japanese vol.].

Tyndale-Biscoe, M. & George, R.W. 1962. The Oxystomata and Gymnopleura (Crustacea, Brachyura) of Western Australia with descriptions of two species from Western Australia and one from India. Journal of the Royal Society of Western Australia 45(3): 65-96 figs 1-9 pls 1-3

 

History of changes

Published	As part of group	Action Date	Action Type	Compiler(s)
10-May-2022	DECAPODA Latreille, 1802	10-May-2022	MODIFIED
04-Aug-2021	BRACHYURA Latreille, 1802	04-May-2022	MODIFIED	Dr Genefor Walker-Smith (NMV)
05-Aug-2020	DECAPODA Latreille, 1802	10-May-2022	MODIFIED
05-Dec-2019	DECAPODA Latreille, 1802	10-May-2022	MODIFIED	Dr Shane Ahyong
22-Dec-2016	DECAPODA Latreille, 1803	10-May-2022	MODIFIED	Dr Shane Ahyong
04-Jun-2012		04-Jun-2012	MOVED
10-May-2012		10-May-2022	MODIFIED
		12-Feb-2010	(import)