从线粒体16S rDNA序列探讨绒螯蟹类的系统发生关系

测定了绒螯蟹类各物种的线粒体16SrDNA部分片段的序列，构建了NJ树、ML树和MP树。序列歧异数据比较和各系统发生树都支持新绒螯蟹属(Neoeriocheir)为一个独立的属。在3种系统发生树中，直额绒螯蟹(Eriocheir recta)都是绒螯蟹属(Eriocheir)所有其它成员的姐妹群，并且广东珠江1只直额绒螯蟹标本的16SrDNA部分序列与台湾产台湾绒螯蟹(Eriocheir formasa)的相应序列相同。这些结果不支持平绒螯蟹属(Platyeriocheir)是一个有效的属，并表明E．formosa是E．recta的同物异名。绒螯蟹属(Eriocheir)所有其它成员聚为一个单系的分支，支持中华绒螯蟹、合浦绒螯蟹与日本绒螯蟹属于同一个物种Eriocheir japonica。16SrDNA部分序列的比对表明，产于台湾的日本绒螯蟹的此段序列与合浦绒螯蟹的相同，产于崇明岛的和产于美国旧金山海湾的中华绒螯蟹的此段序列与中华绒螯蟹单元型B的序列相同。

Phylogenetic relationships of the mitten crabs inferred from mitochondrial 16S rDNA partial sequences (Crustacean, Decapoda)

Partial sequences of the mitochondrial 16S rRNA gene were determined for all species of the mitten crabs and two species of the Grapsoidea. Neighbor joining (NJ), maximum likelihood (ML) and maximum parsimony (MP) trees were generated using Sesarma dehaani and Grapsus grapsus as outgroup species. The establishment of a separate genus Neoeriocheir is supported by sequence divergence comparisons and the phylogenetic trees. Eriocheir recta was the sister group of all other members of the genus Eriocheir in all phylogenetic trees, and the partial sequence of 16S rDNA of an Eriocheir recta specimen from the Pearl River, Guangdong, is identical to that of Eriocheir formosa from Taiwan. These results do not provide justification for the recognition of Platyeriochei as a valid genus and indicate that E. formosa may have to be synonymized with E. recta. The other members of the genus Eriocheir, E. japonica, E. sinensis and E. hepuensis, clustered in a monophyletic clade and provide evidence for the conspecific status of these taxa. These taxa should be assigned to Eriocheir japonica. The alignment of the 16S rDNA partial sequences indicate that the sequence of Eriocheir japonica from Taiwan (AF105242) is identical to that of E. j. hepuensis , and the sequence of E. sinensis from San Francisco Bay (Schubart,2000) and Chongming Island is identical to that of haplotype B of E. j. sinensis from the Yangtze River and Liaoning.