Molecular systematics of the Asian mitten crabs, genus Eriocheir (Crustacea : Brachyura)

To help resolve phylogenetic relationships among the mitten crabs, complete sequences of the nuclear DNA internal transcribed spacer (ITS) and portions of the mitochondrial genome corresponding to the cytochrome oxidase I (COI), were sequenced for all Asian mitten crabs of the genus Eriocheir and seven species of the Grapsoidea. The resulting phylogeny supports the establishment of a separate genus Neoeriocheir, but does not provide justification for the recognition of Platyeriocheir. A female mitten crab specimen from the Zhujiang River, China, was considered to be Eriocheir recta (Stimpson, 1858), a species previously synonymized with Eriocheir japonica (de Haan, 1835). In the ITS analysis, a sequence from Eriocheir formosa (from Taiwan) falls within a well-supported E recta group, which indicates that E formosa may have to be synonymized with E recta. Three previously recognized members of the genus, E japonica, Eriocheir sinensis, and Eriocheir hepuensis constitute a monophyletic sister group to E recta in all phylogenetic trees. We provide evidence for the conspecific status of these taxa. Phylogenetic trees based on COI and combined COI and ITS sequences indicate that E japonica consists of three subgroups. Since the name E japonica (de Haan, 1835) takes precedence over E sinensis (H. Milne Edwards, 1853) and E. hepuensis Dai, 1991, we suggest that these three subgroups correspond to three subspecies of E. japonica: E. j. japonica, E. j. sinensis, and E. j. hepuensis. (C) 2003 Elsevier Science (USA). All rights reserved.