Biogeography and phylogenetic position of Enchodeloides signyensis (Loof, 1975), gen. n., comb. n. from Maritime Antarctic (Nematoda, Nordiidae)

By

Elshishka, Milka
Lazarova, Stela
Radoslavov, Georgi
Hristov, Peter
Peneva, Vlada

Type

Article

Date of Publication

2017

Original Publication

ZooKeys

Volume

697

Pages

37-58

Subjects

18S and D2-D3 rDNA , Distribution , Morphology , SEM , SNPs , taxonomy

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/zookeys.697.13770

 

Abstract

The taxonomic position of the endemic Antarctic species Enchodeloides signyensis (Loof, 1975), gen. n., comb. n. (= Enchodelus signyensis Loof, 1975) is discussed on the basis of morphological study, including SEM, morphometric data, postembryonic observations, and sequence data of 18S rDNA and the D2-D3 expansion fragments of the large subunit rDNA. A number of characters such as the cuticle and stoma structures, including the presence of moderately developed cuticularised ring around the oral aperture, peculiarities of pharynx expansion, size and position of the posterior pair of pharyngeal nuclei, a less complex uterus, and the position of a posterior ventromedian supplement show that this species differs substantially from the other members of the genus Enchodelus. Furthermore, both the 18S and 28S rDNA-based phylogenetic trees of the Enchodelus sequences available in the GenBank formed two distinct clusters with E. signyensis being a part of a well-supported group with species of the genus Pungentus; therefore, it is proposed that its taxonomic position should be reconsidered.