The new freshwater crab belongs to the genus Geothelphusa as inferred from mitochondrial and nuclear DNA markers

Abstract

This is the first report of a freshwater crab (Naju crab) collected from the Korean peninsula. It was named after Naju city. The Naju crab was identified based on evidence of 2 mitochondrial DNA of 16S rDNA and cytochrome oxidase subunit1 (COI), supporting that the Naju crab belongs to the genus Geothelphusa. The variances of the nucleotide sequence of 16S rDNA are from 2.01% to 6.02% between the Naju crab and four G. dehaani isolates (AB290630, AB551391, AB187570, and AB535460, respectively). The variances of the nucleotide sequence of CO1 are from 2.58% to 7.96% between the Naju crab and four G. dehaani isolates (AB551393, AB187570, AB290648, and AB535491, respectively). The nuclear internal transcribed spacer (ITS) sequence (1515bp) of the Naju crab showed that its 5.8S nucleotide sequence was highly conserved to that of Sesarma spp, terrestrial crab endemic to the American continent. However, the nucleotide sequences of the ITS1 and the ITS2 are not found to be conserved in any species in the world.