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Morphological and Molecular Characterization of Five Species Including Three New Species of Golden Gorgonians (Cnidaria: Octocorallia) from Seamounts in the Western Pacific

SIMPLE SUMMARY: Deep-water octocorals are main components of vulnerable marine ecosystems (VMEs) and play an important role in conservation and research. Iridogorgia Verill, 1883 is a distinct octocoral group characterized by a remarkably spiral structure and large size in deep sea, where the divers...

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Autores principales: Xu, Yu, Zhan, Zifeng, Xu, Kuidong
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8301098/
https://www.ncbi.nlm.nih.gov/pubmed/34206888
http://dx.doi.org/10.3390/biology10070588
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author Xu, Yu
Zhan, Zifeng
Xu, Kuidong
author_facet Xu, Yu
Zhan, Zifeng
Xu, Kuidong
author_sort Xu, Yu
collection PubMed
description SIMPLE SUMMARY: Deep-water octocorals are main components of vulnerable marine ecosystems (VMEs) and play an important role in conservation and research. Iridogorgia Verill, 1883 is a distinct octocoral group characterized by a remarkably spiral structure and large size in deep sea, where the diversity of Iridogorgia is poorly known in the Western Pacific. Based on the collection of Iridogorgia specimens from seamounts in the tropical Western Pacific, we described five species including three new species using an integrated morphological-molecular approach. We assessed the potential of the mitochondrial genes MutS and COI, and the nuclear 28S rDNA for species delimitation and phylogenetic reconstruction of Iridogorgia. The results suggest that the mitochondrial markers are not able to resolve the species boundaries and deeply divergent relationships adequately, while 28S rDNA showed potential application in DNA barcoding and phylogenetic reconstruction for this genus. This study will help to understand the Iridogorgia biodiversity in the Western Pacific and shed more light on the screening of barcodes for octocorals. ABSTRACT: Members of genus Iridogorgia Verrill, 1883 are the typical deep-sea megabenthos with only seven species reported. Based on an integrated morphological-molecular approach, eight sampled specimens of Iridogorgia from seamounts in the tropical Western Pacific are identified as three new species, and two known species I. magnispiralis Watling, 2007 and I. densispicula Xu, Zhan, Li and Xu, 2020. Iridogorgia flexilis sp. nov. is unique in having a very broad polyp body base with stout and thick scales. Iridogorgia densispiralis sp. nov. can be distinguished by rods present in both polyps and coenenchyme, and I. verrucosa sp. nov. is characterized by having numerous verrucae in coenenchyme and irregular spindles and scales in the polyp body wall. Phylogenetic analysis based on the nuclear 28S rDNA indicated that I. densispiralis sp. nov. showed close relationships with I. splendens Watling, 2007 and I. verrucosa sp. nov., and I. flexilis sp. nov. formed a sister clade with I. magnispiralis. In addition, due to Rhodaniridogorgia fragilis Watling, 2007 nested into the Iridogorgia clade in mtMutS-COI trees and shared highly similar morphology to the latter, we propose to eliminate the genus Rhodaniridogorgia by establishing a new combination Iridogorgia fragilis (Watling, 2007) comb. nov. and resurrecting I. superba Nutting, 1908.
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spelling pubmed-83010982021-07-24 Morphological and Molecular Characterization of Five Species Including Three New Species of Golden Gorgonians (Cnidaria: Octocorallia) from Seamounts in the Western Pacific Xu, Yu Zhan, Zifeng Xu, Kuidong Biology (Basel) Article SIMPLE SUMMARY: Deep-water octocorals are main components of vulnerable marine ecosystems (VMEs) and play an important role in conservation and research. Iridogorgia Verill, 1883 is a distinct octocoral group characterized by a remarkably spiral structure and large size in deep sea, where the diversity of Iridogorgia is poorly known in the Western Pacific. Based on the collection of Iridogorgia specimens from seamounts in the tropical Western Pacific, we described five species including three new species using an integrated morphological-molecular approach. We assessed the potential of the mitochondrial genes MutS and COI, and the nuclear 28S rDNA for species delimitation and phylogenetic reconstruction of Iridogorgia. The results suggest that the mitochondrial markers are not able to resolve the species boundaries and deeply divergent relationships adequately, while 28S rDNA showed potential application in DNA barcoding and phylogenetic reconstruction for this genus. This study will help to understand the Iridogorgia biodiversity in the Western Pacific and shed more light on the screening of barcodes for octocorals. ABSTRACT: Members of genus Iridogorgia Verrill, 1883 are the typical deep-sea megabenthos with only seven species reported. Based on an integrated morphological-molecular approach, eight sampled specimens of Iridogorgia from seamounts in the tropical Western Pacific are identified as three new species, and two known species I. magnispiralis Watling, 2007 and I. densispicula Xu, Zhan, Li and Xu, 2020. Iridogorgia flexilis sp. nov. is unique in having a very broad polyp body base with stout and thick scales. Iridogorgia densispiralis sp. nov. can be distinguished by rods present in both polyps and coenenchyme, and I. verrucosa sp. nov. is characterized by having numerous verrucae in coenenchyme and irregular spindles and scales in the polyp body wall. Phylogenetic analysis based on the nuclear 28S rDNA indicated that I. densispiralis sp. nov. showed close relationships with I. splendens Watling, 2007 and I. verrucosa sp. nov., and I. flexilis sp. nov. formed a sister clade with I. magnispiralis. In addition, due to Rhodaniridogorgia fragilis Watling, 2007 nested into the Iridogorgia clade in mtMutS-COI trees and shared highly similar morphology to the latter, we propose to eliminate the genus Rhodaniridogorgia by establishing a new combination Iridogorgia fragilis (Watling, 2007) comb. nov. and resurrecting I. superba Nutting, 1908. MDPI 2021-06-26 /pmc/articles/PMC8301098/ /pubmed/34206888 http://dx.doi.org/10.3390/biology10070588 Text en © 2021 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Xu, Yu
Zhan, Zifeng
Xu, Kuidong
Morphological and Molecular Characterization of Five Species Including Three New Species of Golden Gorgonians (Cnidaria: Octocorallia) from Seamounts in the Western Pacific
title Morphological and Molecular Characterization of Five Species Including Three New Species of Golden Gorgonians (Cnidaria: Octocorallia) from Seamounts in the Western Pacific
title_full Morphological and Molecular Characterization of Five Species Including Three New Species of Golden Gorgonians (Cnidaria: Octocorallia) from Seamounts in the Western Pacific
title_fullStr Morphological and Molecular Characterization of Five Species Including Three New Species of Golden Gorgonians (Cnidaria: Octocorallia) from Seamounts in the Western Pacific
title_full_unstemmed Morphological and Molecular Characterization of Five Species Including Three New Species of Golden Gorgonians (Cnidaria: Octocorallia) from Seamounts in the Western Pacific
title_short Morphological and Molecular Characterization of Five Species Including Three New Species of Golden Gorgonians (Cnidaria: Octocorallia) from Seamounts in the Western Pacific
title_sort morphological and molecular characterization of five species including three new species of golden gorgonians (cnidaria: octocorallia) from seamounts in the western pacific
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8301098/
https://www.ncbi.nlm.nih.gov/pubmed/34206888
http://dx.doi.org/10.3390/biology10070588
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