Three new species and one new record of Deimatidae (Echinodermata, Holothuroidea, Synallactida) discovered in the South China Sea and the Mariana fore-arc area using integrative taxonomic methods

By

Xiao, Yunlu
Zhang, Haibin

Type

Article

Date of Publication

2024

Original Publication

ZooKeys

Volume

1195

Pages

309--335

Subjects

COI , deep-sea , Morphology , Oneirophanta , Phylogeny , Sea cucumber , SEM , taxonomy

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/zookeys.1195.115913

 

Abstract

Deep-sea holothurian specimens were collected during five scientific expeditions (2018–2023) using the submersible vehicle ‘Shenhaiyongshi’. Our examination of specimens of Deimatidae from the South China Sea and the Mariana fore-arc area revealed three new species, which were described as Oneirophanta idsseicasp. nov., Oneirophanta brunneannulatasp. nov., and Oneirophanta lucernasp. nov. These species were distinguished from each other and from congeners by the arrangement, and number of ventrolateral tube feet and ossicle types. We also reported Oneirophanta mutabilis mutabilis Théel, 1879 for the first time from the Mariana fore-arc area, and we recorded Deima validum validum for the second time from the South China Sea. The taxonomy of these new species and new records is discussed, and a phylogenetic analysis based on a concatenated dataset of 16S and COI genes was conducted. Additionally, the inter- and intraspecific genetic divergences we calculated among deimatid species. The results support the assignment of these new species to the genus Oneirophanta and their separation from congeners. A description of the main morphological characters of Oneirophanta species is also provided. The data were collected from geographically diverse areas and suggest that species of Deimatidae were abundant in the Pacific Ocean and occupied a wide range of depths.