Meeting Abstract

33.8  Friday, Jan. 4  Xanthid crab (Crustacea: Decapoda: Brachyura) classification and phylogeny: an appraisal using the setotaxy of first stage zoeas. CLARK, Paul F.; The Natural History Museum, London p.clark@nhm.ac.uk

Xanthoidean crabs are common and speciose in macrofaunal communities of reef habitats worldwide. There are probably more genera assigned to the superfamily Xanthoidea MacLeay, 1838 (sensu Guinot, 1978) than to any other taxon in the Brachyura Latreille, 1802. Difficulties in classifying this generic-level diversity and species richness have resulted in major systematic problems within the group. For example four adult-based xanthoid classifications have been suggested, Balss (1957), Glaessner (1969) and Guinot (1978), together with that proposed by Martin and Davis (2001) after wide consultation with the crustacean research community. The first stage zoeal morphology of one hundred and seventeen xanthoids was used to test the four adult-based classifications. No one classification was fully supported although there was a reasonable degree of congruence with the Xanthoidea of Martin and Davis (2001), largely based on Guinot (1978). This study supported the assignment of the Geryonidae to the Portunoidea, and the validity of the Carpiliidae, Pilumnidae, Trapeziidae and Xanthidae. However there is no consistent support for the thirteen existing subfamilies of the latter.