Iridogorgia is a genus of soft coral that belongs to the family Chrysogorgiidae. It is native to the Atlantic and Pacific Oceans. It lives in deep sea environments and is characterized by its large spiral shape with longs and relatable branches attached to it.
Distribution Species are present in both the Atlantic and Pacific Oceans with two species being predominantly found in the Northern Atlantic Ocean and nine species being restricted to the Pacific Ocean. In the North Atlantic, four species can be found that predominantly inhabit seamounts. They are I. pourtalesii, I. magnispiralis, I. splendens and I. fontinalis. A few species have been recorded to inhabit the coast of the Hawaiian islands such as I. superba, I. bella and I. magnispiralis. The diversity of this genus in the western Pacific Ocean is poorly known. Species that are distributed across both oceans include I. magnispiralis, I. fontinalis, and I. splendens.
It is a genus that lives in the deep sea at depths of 558–2311 meters.
Description It is characterized by an upright-spiraling monopodial axis with long and flexible, unbranched branches arising from one side of the spiral. Many of these branches have brilliant iridescent features. They are usually large in size.
Taxonomy Iridogorgia was described in 1883 by Verrill from collected specimens from coastal expeditions of the southeastern United States and West Indies. The original specimen was collected from Dominica at a depth of 991 meters. In 1908, Nutting described two species that were collected in dredge hauls of the coast of the main Hawaiian Islands by the US Fish Commission Steamer ‘Albatross’. The first species, I. superba, was nearly complete while the second, I. bella, was severely damaged with only a few branches left attached.
Species This genus currently contains 16 described species. They are listed below:
Iridogorgia acutisclerita Ge, Zhang & Xu., 2026 Iridogorgia bella Nutting, 1908 Iridogorgia chewbacca Xu, Watling & Xu in Xu et al., 2025 Iridogorgia curva Xu, Watling & Xu in Xu et al., 2025 Iridogorgia densispicula Xu, Zhan, Li & Xu, 2020 Iridogorgia densispiralis Xu, Zhan & Xu, 2021 Iridogorgia flexilis Xu, Zhan & Xu, 2021 Iridogorgia fontinalis Watling, 2007 Iridogorgia fragilis (Watling, 2007) Iridogorgia levisquama Ge, Zhang & Xu., 2026 Iridogorgia magnispiralis Watling, 2007 Iridogorgia pourtalesii Verrill, 1883 Iridogorgia splendens Watling, 2007 Iridogorgia squarrosa Xu, Zhan, Li & Xu, 2020 Iridogorgia superba Nutting, 1908 Iridogorgia verrucosa Xu, Zhan & Xu, 2021
Synonyms Rhodaniridogorgia is currently considered to be a taxonomic synonym of the genus Iridogorgia. It was described along with I. magnispiralis by Watling in 2007 based on the wavy axis. However later morphological and phylogenetic analyses supports Rhodaniridogorgia (now I. superba) being a synonym of this genus.
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