First Record of Ophidonais serpentina (Müller, 1773) (Oligochaeta: Naididae) in China: The Occurrence or Absence of Needles Are Intraspecific Differences

Abstract

A naidid oligochaete, Ophidonais serpentina (Müller, 1773) is redescribed based on specimens from the Xinkai River in Zhejiang Province, China. O. serpentina is very common in Europe and America. This study is the first record of the species in China. By integrating the previously morphological descriptions related to O. serpentina in the world, it can be divided into three morphological groups: a group with dorsal chaetae starting from VI, a group without dorsal chaetae, and a group with an unstable starting position of the dorsal chaetae. By comparing the mitochondrial DNA (16S rDNA, COI), nuclear DNA (ITS2), and histones (H3) from the three groups, Bayesian inference and maximum likelihood phylogenetic analyses were performed based on the combined data set. Different analyses gave almost consistent phylogenetic trees. All of the genetic distances between the three groups were 0.00%. No genetic variation can be detected between the specimens regardless of the presence and starting position of dorsal chaetae. This result suggests that a single lineage of O. serpentina is widespread worldwide.