A new quadrannulate species of Orobdella (Hirudinida, Arhynchobdellida, Orobdellidae) from central Honshu, Japan.

Takafumi Nakano

doi:10.3897/zookeys.445.7999

Abstract

A new quadrannulate species of Orobdella, Orobdella masaakikuroiwai sp. n., from the mountainous region of central Honshu, Japan is described. This is only the second small species known within this genus, with a body length of less than 4 cm for mature individuals. Phylogenetic analyses using nuclear 18S rDNA and histone H3 as well as mitochondrial COI, tRNACys, tRNAMet, 12S, tRNAVal, 16S, and ND1 markers showed that Orobdella masaakikuroiwai sp. n. is the sister species of the quadrannulate Orobdella whitmani Oka, 1895. Phylogenetic relationships within Orobdella masaakikuroiwai sp. n. conducted using mitochondrial markers reveled a distinction between eastern and western phylogroups.

Highlights

The genus Orobdella Oka, 1895 is an East Asian terrestrial macrophagous leech taxon assigned to the family Gastrostomobdellidae Richardson, 1971, along with the Southeast Asian terrestrial macrophagous genus Gastrostomobdella Moore, 1929 (Richardson1971)
The monotypic family Orobdellidae Nakano, Ramlah & Hikida, 2012 was established for Orobdella based on both morphological differences between Orobdella and Gastrostomobdella and the results of an analysis by Nakano et al (2012) which rejected the monophyly of these two taxa
The phylogenetic position of the new species within the genus Orobdella was estimated based on sequences of nuclear 18S and H3 and mitochondrial COI, tRNACys

Summary

Introduction

The genus Orobdella Oka, 1895 is an East Asian terrestrial macrophagous leech taxon assigned to the family Gastrostomobdellidae Richardson, 1971, along with the Southeast Asian terrestrial macrophagous genus Gastrostomobdella Moore, 1929 The monotypic family Orobdellidae Nakano, Ramlah & Hikida, 2012 was established for Orobdella based on both morphological differences between Orobdella and Gastrostomobdella (gastroporal duct of Orobdella is tubular and positioned on top of the female organ while in Gastrostomobdella, this duct is columnar and vertical in position to the gastropore) and the results of an analysis by Nakano et al (2012) which rejected the monophyly of these two taxa. Despite their failure to reconstruct the precise phylogenetic relationships of Orobdella and Gastrostomobdella within Erpobdelliformes, the classification by Nakano et al (2012) is followed here. The phylogenetic position of this new species was reconstructed using nuclear 18S and histone H3 (H3), and mitochondrial COI, tRNACys, tRNAMet, 12S, tRNAVal and 16S rDNA, and ND1 sequence data

Materials and methods

10 August 2012

Findings

Discussion