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Systematics, phylogeny and biogeography
RESEARCH ARTICLE

Unexpected species diversity within Japanese Mundochthonius pseudoscorpions (Pseudoscorpiones : Chthoniidae) and the necessity for improved species diagnosis revealed by molecular and morphological examination

Hajime Ohira A D , Shingo Kaneko B , Leanne Faulks C and Tadaaki Tsutsumi B
+ Author Affiliations
- Author Affiliations

A Graduate School of Symbiotic Systems Science and Technology, Fukushima University, Kanayagawa 1, Fukushima City, Fukushima Prefecture 960-1296, Japan.

B Faculty of Symbiotic Systems Science, Fukushima University, Kanayagawa 1, Fukushima City, Fukushima Prefecture 960-1296, Japan.

C Sugadaira Research Station, Mountain Science Center, University of Tsukuba, Sugadaira 1278-294, Sugadaira-Kogen, Ueda City, Nagano Prefecture 386-2204, Japan.

D Corresponding author. Email: ohira.hajime@gmail.com

Invertebrate Systematics 32(2) 259-277 https://doi.org/10.1071/IS17036
Submitted: 6 April 2017  Accepted: 18 July 2017   Published: 22 March 2018

Abstract

Using the complementary approaches of morphological and molecular taxonomy is essential to further our understanding of invertebrate diversity, including the identification of cryptic species. Although the species classification of a widespread group of arachnids, the pseudoscorpions, has been based on traditional diagnostic characters for a long time, recent taxonomic studies have suggested that some of these are unreliable for distinguishing species. Thus, the application of molecular taxonomy may be particularly useful in this group. Here, we performed molecular phylogenetic analyses and species delimitation analyses based on partial sequences of mitochondrial DNA cytochrome c oxidase I and nuclear DNA 18S rRNA genes to assess the taxonomy of species and the reliability of morphological characteristics for distinguishing species in the Japanese soil-dwelling genus Mundochthonius (Chthoniidae). Our results revealed the existence of seven major genetic clades, likely corresponding to three described species and four cryptic species. Although two described species, M. kiyoshii and M. itohi, were represented by single clades in the phylogenetic analysis, a third, M. japonicus, was composed of multiple clades, highlighting inconsistencies between phylogenetic relationships and current species classifications using traditional morphological diagnostics. This study exemplifies the need for further exploration of pseudoscorpion taxonomy and species diversity. In particular, detailed morphological examinations are expected to help determine differences among cryptic species.

Additional keywords: 18S, Arachnida, classification, cryptic species, cytochrome c oxidase I, soil.


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