A new eyeless species of Nereis (Annelida, Nereididae) from deep-sea sediments of the northern South China Sea

By

Lin, Jun-hui
Huang, Ya-Qin
Liang, Qianyong
He, Xue-Bao

Type

Article

Date of Publication

2022

Original Publication

ZooKeys

Volume

1134

Pages

23--37

Subjects

Nereidiformia , Phylogeny , Polychaete , systematics , taxonomy

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/zookeys.1134.94198

 

Abstract

A variety of nereidid species have been reported from the South China Sea, although little is known about the deep-sea species in this area. Recently, two specimens belonging to a novel nereidid polychaete were collected from a sedimentary habitat during an environmental survey to a deep-sea basin where cold seeps occur. This new species, Nereis tricirratasp. nov., is described herein, based on morphological and molecular analyses. The most noteworthy feature is the absence of eyes on the prostomium; it can be distinguished from other eyeless Nereis species by the arrangement of conical paragnaths on the pharynx, the nature of homogomph falcigers and the shape of notopodial lobes in posterior chaetigers. The reconstructed phylogenetic tree, using concatenated sequences of mtCOI, 16S, and 18S rRNA, showed that all Nereis species included in this study form a monophyletic clade with full support. The mtCOI-based interspecific comparisons revealed a high genetic divergence (23.1%–37.3% K2P) from four-eyed Nereis species with the available sequences. This is the first record of an eyeless Nereis species in the South China Sea.