Meeting Abstract

1.4  Jan. 4  Mitochondrial DNA Phylogeny of the Family Dorippidae (Decapoda, Brachyura) SIN, Y. W. *; CHU, K. H. ; NG, P. K. L.; The Chinese University of Hong Kong; The Chinese University of Hong Kong; National University of Singapore kahouchu@cuhk.edu.hk

Crabs of the family Dorippidae are unusual in that they have reduced fourth and fifth pairs of pereopods which are specially modified for carrying objects. There are two subfamilies of Dorippidae (Dorippinae and Ethusinae), with a total of 97 species from around the world. The affinities of the Dorippidae, between other brachyuran lineages and within the family, however, are very poorly known. In the present study, the phylogeny of the Dorippidae is investigated using three mitochondrial gene segments: 12S rRNA, 16S rRNA and COI. Fifteen species from nine of the 12 extant dorippid genera are included in the analysis. The result supports monophyly of each of the subfamilies, with Ethusina and Ethusa (Ethusinae) clearly distinct from the seven genera of Dorippinae studied. In the Dorippinae, Dorippe, Medorippe and Dorippoides always form a clade, while Neodorippe, Heikea, Paradorippe and Philippidorippe form another clade, with the former two genera being most closely related and Philippidorippe being the most distant taxon in the clade. This analysis provides insights into the evolutionary relationships within this family. Comparing the divergence among the Dorippidae and other related brachyuran families suggest a deep break between the two subfamilies.