Description of a new species of Paraplehnia (Polycladida, Stylochoidea) from Japan, with inference on the phylogenetic position of Plehniidae

By

Oya, Yuki
Kimura, Taeko
Kajihara, Hiroshi

Type

Article

Date of Publication

2019

Original Publication

ZooKeys

Volume

864

Pages

1-13

Subjects

28S rDNA , Acotylea , Bayesian Inference , COI , marine flatworm , maximum likelihood , taxonomy

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/zookeys.864.33955

 

Abstract

We describe a new species of polyclad flatworm,Paraplehniaseisuiaesp. nov., from 298–310 m depths in the Sea of Kumano, West Pacific, Japan.Paraplehniaseisuiaesp. nov.is characterized by i) a developed muscular wall proximally occupying about one-third of the prostatic vesicle, ii) no common duct between the spermiducal bulbs and the prostatic vesicle, and iii) a genital pit between the male and female gonopores. We provide a partial sequence (712 bp) of the mitochondrial cytochromecoxidase subunit I gene as a DNA barcode for the species. Our phylogenetic analyses based on 603-bp 28S rDNA sequences indicate thatP.seisuiaesp. nov.is nested in a clade consisting of stylochoid species along with unidentified species ofStylochus. It suggests that Plehniidae belongs to Stylochoidea, although this should be confirmed by future studies that containPlehniaarctica(Plehn, 1896), the type species of the type genus of the family. The interfamily relationship among the superfamily Stylochoidea remains poorly resolved.