Two new species add to the diversity of Eoniphargus in subterranean waters of Japan, with molecular phylogeny of the family Mesogammaridae (Crustacea, Amphipoda)

By

Shintani, Aki
Lee, Chi-Woo
Tomikawa, Ko

Type

Article

Date of Publication

2022

Original Publication

Subterranean Biology

Volume

44

Pages

21--50

Subjects

cryptic species , interstitial water , molecular phylogeny , new species , taxonomy

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/subtbiol.44.86914

 

Abstract

Amphipod crustaceans are a major group of invertebrates that predominantly occur in groundwater ecosystems. Eoniphargus is a mesogammarid genus with only two known species from the groundwater systems of the Japanese archipelago and Korean Peninsula. However, there is a dearth of taxonomic studies on this genus, and the species diversity within Eoniphargus is unclear. Here, we describe two new species, E. iwataorumsp. nov. and E. toriiisp. nov., collected from the interstitial waters in Tochigi and Shizuoka Prefectures in the Japanese archipelago. These two new species are distinguished from their congeners by the following features: head, urosomite 3, first and second antennae, mandibles, and maxilla 1. Eoniphargus kojimai is redescribed here based on material collected near the type locality. Molecular phylogenetic analyses based on the nuclear 28S rRNA and mitochondrial COI genes revealed that E. kojimai is sister to E. iwataorumsp. nov. In this study, we also briefly discuss the phylogenetic relationships of Mesogammaridae based on the molecular phylogenetic analyses.