[Cnidaria • 2026] Chrysogorgia pugnioides, Iridogorgia acutisclerita, I. levisquama • Systematics and Biogeography of Chrysogorgiidae (Anthozoa: Octocorallia) from the Indian Ocean: discovery of New Species on Deep-sea Ridges

Iridogorgia acutisclerita Ge, Zhang & Xu,

in Ge, N. Xu, Hu, Tian, Li, Y. Xu, Wang, Zhang et Q. Xu, 2026. 

DOI: doi.org/10.3897/zse.102.182492 

Abstract

Species of the family Chrysogorgiidae are distributed worldwide in deep-sea environments. However, most recorded species of this family were from the Atlantic and Pacific Oceans, with only a few reports from the Indian Ocean, particularly from ridge regions. This study describes three new species and reports two known species from Indian Ocean ridges, integrating morphological and molecular analyses (mtMutS and 28S rDNA). Chrysogorgia pugnioides Ge, Hu & Xu, sp. nov. is characterized by fist-like polyps; warty spindles in tentacles; flat and irregular spindles and elongate scales in the polyp body wall; and slender and smooth scales with toothed to irregular edges in the coenenchyme. Iridogorgia acutisclerita Ge, Zhang & Xu, sp. nov. resembles I. splendens but differs by possessing needles and pointed elongate scales in the polyp body wall. Iridogorgia levisquama Ge, Zhang & Xu, sp. nov. is differentiated from the congeneric I. squarrosa by slender and smooth scales with sharp ends in the polyp body wall and needles with fine wartiness in the tentacles. Parachrysogorgia chryseis and Metallogorgia melanotrichos are reported as new records for the Indian Ocean ridges. These findings expand the known biodiversity and biogeographic range of Chrysogorgiidae in the Indian Ocean ridges.

Key Words: Carlsberg Ridge, Chrysogorgiidae, Ninetyeast Ridge, phylogeny, taxonomy

Chrysogorgia pugnioides Ge, Hu & Xu, sp. nov.  

Iridogorgia acutisclerita Ge, Zhang & Xu, sp. nov. 

Iridogorgia levisquama Ge, Zhang & Xu, sp. nov.

The external morphology of Iridogorgia acutisclerita Ge, Zhang & Xu, sp. nov.
 A. Holotype FIO-IND72-JLBEN22309 in situ; B. Paratype FIO-IND72-JLBEN22402 in situ; C–E. Holotype FIO-IND72-JLBEN22309, paratype FIO-IND72-JLBEN22402, and FIO-IND72-JLBEN225511 after collection;
F. Single polyp under a light microscope; G. Single polyp under SEM; H. A part of the tentacle under SEM; I. A part of the branch under a light microscope; J. A part of the branch with epidermal tissue removed under SEM; K. A part of the branch with epidermal tissue under SEM.

Scale bars: 20 cm (C–E); 1 mm (F, I); 500 μm (G, K); 250 μm (H, J).

 Meiling Ge, Ningxia Xu, Xuying Hu, Xin Tian, Xinlong Li, Yu Xu, Zongling Wang, Xuelei Zhang and Qingzeng Xu. 2026. Systematics and Biogeography of Chrysogorgiidae from the Indian Ocean: discovery of New Species on Deep-sea Ridges. Zoosystematics and Evolution. 102(2): 621-647.  DOI: doi.org/10.3897/zse.102.182492 [07 Apr 2026]