Two new species of deep-sea Red Corals (Coralliidae, Genus Hemicorallium Gray, 1867) from the western Indian Ocean

By

Hu, Xuying
Zhang, Qian
Ge, Meiling
Li, Xinlong
Wang, Zongling
Zhang, Xuelei
Xu, Qinzeng

Type

Article

Date of Publication

2025-2-14

Original Publication

Zoosystematics and evolution

Volume

101

Series / Issue

Issue: 1

Pages

317--339

Subjects

deep-sea corals , Hemicorallium , Indian Ocean , molecular phylogenetics , morphological description , new species

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia Pensoft

Identifiers

DOI: https://doi.org/10.3897/zse.101.139350

 

Abstract

Deep-sea corals are critical to global exploration of deep-sea biodiversity, but research on them in the Indian Ocean is very limited. In this study, we report the first discovery of two new species of red corals at a depth of 1697 m in the western Indian Ocean. The species were identified through detailed morphological analysis, including microscopic examination of colony structure, branches and autozooids (assessing size, abundance and spacing), as well as scanning electron microscopy (SEM) of sclerite morphology and quantity. Two species for the genus Hemicorallium Gray, 1867 were found as new species, designated Hemicorallium indicodensumsp. nov. and Hemicorallium jiaolongensissp. nov.H. indicodensumsp. nov. is characterised by densely branched structures and numerous globular double-club sclerites, distinguishing it from other species. Meanwhile, H. jiaolongensissp. nov. features yellowish-white colonies with short rods with sharp, large radial projections in the tentacles. Four mitochondrial regions were used to reveal the phylogenetic relationship in Coralliidae, supporting the taxonomic placement of these two new species. This study provides significant new insights into the biodiversity of deep-sea corals in the Indian Ocean, enriching the known species pool. Additionally, a more comprehensive key to the genus Hemicorallium is provided, further enhancing our understanding of the group’s taxonomy.