A NEW SPECIES OF PERISESARMA (BRACHYURA, SESARMIDAE) FROM WESTERN AUSTRALIA

BY

PETER J.F. DAVIE1) Queensland Museum, P.O. Box 3300, South Brisbane, Queensland, 4101, Australia

ABSTRACT

A new species of sesarmid , Perisesarma holthuisi n. sp., is described from intertidal mangrove creeks on the central coast of Western Australia. It can be separated variously from congeners by male chela characters, including the shape and number of the dactylar tubercles, the pattern of dentition of the cutting margin of the dactylus, the male abdominal shape, and leg proportions. The composition of the genus is reviewed and a key to the Indo-West Pacific species is provided.

RÉSUMÉ

Une nouvelle espèce de crabe Sesarmidae, Perisesarma holthuisi n. sp., est décrite à partir de spécimens récoltés intertidalement dans les chenaux de mangroves de la côte centrale de l’Australie occidentale. Ce crabe se distingue des auther espèces de Perisesarma par divers caractères des chélipèdes du mâle tels que la forme et le nombre des tubercules du dactyle, le pattern de dentition du bord tranchant du dactyle, la forme de l’abdomen du mâle, et les proportions pattes ambulatoires. La composition du genre est ainsi révisée et une clé d’identification est fournie les espèces indo-ouest pacifiques.

INTRODUCTION

Perisesarma De Man, 1895, is one of the larger genera in the family Sesarmidae (sensu Ng et al., 2008), and with the description of the present species, now includes 22 Indo-West Pacific species, and three from the southern Atlantic coast of West Africa. As noted in Ng et al. (2008), the West African species share a number of unique apomorphies and will almost

1) e-mail: [email protected]

© Koninklijke Brill NV, Leiden, 2010 Studies on : 195-207 196 CRM 014 – Fransen et al. (eds.), LIPKE BIJDELEY HOLTHUIS MEMORIAL VOLUME certainly need to be transferred to separate genus as part of ongoing revisionary studies by the present author. The genus Perisesarma De Man, 1895, is now accepted as the correct name for the species previously included in the subgenus (Chiromantes) sensu Tesch (1917) (see Holthuis, 1977: 170-171). Conversely, Chiromantes Gistel, 1848, is the correct available name for the group previously referred to as Holometopus H. Milne Edwards, 1853. Campbell (1967) provided the most recent review of the genus and de- scribed three new species and one new subspecies from Australia. Since then there has been a number of new species described including P.maipoense (Soh, 1978), from Hong Kong, P. f o re s t i and P. cricotum by Rahayu & Davie, 2002 from the mangroves of the southern coast of West Papua, Indonesia, P. ben- galense Davie, 2003, from the Bay of Bengal, and P. s a m a w a t i Gillikin & Schubart, 2004, from East Africa. Given the recent changes, it was considered that a revised key to the genus would be helpful, and this is provided in the present paper. The specimens for this study were collected by Barry Wilson as part of environmental impact assessments on the Ashburton River region, on the mid- west coast of Western Australia, and forwarded to the present author for identification and study, by Andrew Hosie of the Western Australian Museum, Perth. Specimens are deposited in the Western Australian Museum, Perth (WAM) and the Queensland Museum, Brisbane (QM). Measurements (in mm) given in the text are of the carapace breadth (measured at the widest point) followed by length, for the biggest and smallest specimen. c.b. = carapace breadth; G1 = male first gonopod.

TAXONOMY

Perisesarma De Man, 1895

Perisesarma De Man, 1895: 208; Ng et al., 2008: 222. Sesarma (Perisesarma): De Man, 1902: 541; Holthuis, 1977: 170-171. Sesarma (Chiromanthes): Rathbun, 1909: 22; 1910: 309; 1918: 284; Tesch, 1917: 235, 255; Campbell, 1967: 2. Type species. — Sesarma dussumieri A. Milne-Edwards, 1853, designated by Campbell (1967: 2); not S. bidens (De Haan) as designated by Rathbun (1918: 284) as that species was not originally included in Perisesarma by de