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Issue: Vol. 5689 No. 3: 4 Sept. 2025
Type: Article
Published: 2025-09-04
DOI: 10.11646/zootaxa.5689.3.3
Page range: 451-486
Abstract views: 165
PDF downloaded: 2

Studies on western Pacific gorgonians (Anthozoa: Octocorallia: Chrysogorgiidae). Part 2: unexpected diversity of the genus Iridogorgia in the tropical western Pacific with descriptions of two new species

Laboratory of Marine Organism Taxonomy and Phylogeny; Qingdao Key Laboratory of Marine Biodiversity and Conservation; Shandong Province Key Laboratory of Experimental Marine Biology; Institute of Oceanology; Chinese Academy of Sciences; Qingdao 266071; China.
School of Life Sciences; University of Hawaii at Manoa; Honolulu; Hawaii 96822; USA.
Laboratory of Marine Organism Taxonomy and Phylogeny; Qingdao Key Laboratory of Marine Biodiversity and Conservation; Shandong Province Key Laboratory of Experimental Marine Biology; Institute of Oceanology; Chinese Academy of Sciences; Qingdao 266071; China.
Laboratory of Marine Organism Taxonomy and Phylogeny; Qingdao Key Laboratory of Marine Biodiversity and Conservation; Shandong Province Key Laboratory of Experimental Marine Biology; Institute of Oceanology; Chinese Academy of Sciences; Qingdao 266071; China.; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai); Zhuhai 519082; China.; University of Chinese Academy of Sciences; Beijing 100049; China.
Diptera deep sea morphology phylogeny seamount taxonomy

Abstract

Species of the genus Iridogorgia Verrill, 1883 are typical deep-sea organisms, characterized by monopodial and spiral axis with a brilliant iridescence. Utilizing an integrated morphological-molecular approach, twelve specimens of Iridogorgia obtained from the tropical western and central Pacific were described as two new species I. curva sp. nov. and I. chewbacca sp. nov., and four known species. Additionally, I. fontinalis Watling, 2007 and I. splendens Watling, 2007 are two new recorded species in the Western Pacific Ocean. Iridogorgia verrucosa Xu, Zhan & Xu, 2021 and I. squarrosa Xu, Zhan, Li & Xu, 2020 are described again. There are currently fourteen species of Iridogorgia with twelve species in the Pacific. Among them, ten species were found in the tropical western Pacific, showing a high diversity. This study indicates the direction of growth (clockwise or counter-clockwise) is not a useful taxonomic character for Iridogorgia species identification. Phylogenetic analyses, based on both mtMutS-cox1 and 28S rDNA sequences, substantiated the taxonomic designation of the new species, I. chewbacca sp. nov. However, the mtMutS and mtMutS-cox1 showed very limited usefulness for species delimitation and inner relationship inference of most Iridogorgia species, while the 28S rDNA showed much higher level of genetic variation.

 

References

  1. Alfaro, M.E., Zoller, S. & Lutzoni, F. (2003) Bayes or Bootstrap? A simulation study comparing the performance of Bayesian Markov chain Monte Carlo sampling and bootstrapping in assessing phylogenetic confidence. Molecular Biology and Evolution, 20 (2), 255–266. https://doi.org/10.1093/molbev/msg028
  2. Bayer, F.M., Grasshoff, M. & Verseveldt, J. (1983) Illustrated Trilingual Glossary of Morphological and Anatomical Terms Applied to Octocorallia. E.J. Brill/Dr. W. Backhuys, Leiden, 75 pp. https://doi.org/10.1163/9789004631915
  3. Ehrenberg, C.G. (1834) Beiträge zur physiologischen Kenntniss der Corallenthiere im allgemeinen, und besonders des rothen Meeres, nebst einem Versuche zur physiologischen Systematik derselben. Abhandlungen der Königlichen Akademie der Wissenschaften, Berlin, 1, 225–380.
  4. Haeckel, E. (1866) Generelle morphologie der Organismen. Vol. 2. Verlag von Georg Reimer, Berlin, 652 pp. https://doi.org/10.1515/9783110848281
  5. Hall, T.A. (1999) BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic Acids Symposium Series, 41, 95–98.
  6. Herrera, S., Baco, A. & Sánchez, J.A. (2010) Molecular systematics of the bubblegum coral genera (Paragorgiidae, Octocorallia) and description of a new deep-sea species. Molecular Phylogenetics and Evolution, 55 (1), 123–135. https://doi.org/10.1016/j.ympev.2009.12.007
  7. Hillis, D.M. & Bull, J.J. (1993) An empirical test of bootstrapping as a method for assessing confidence in phylogenetic analysis. Systematic Biology, 42 (2), 182–192. https://doi.org/10.1093/sysbio/42.2.182
  8. Kalyaanamoorthy, S., Minh, B.Q., Wong, T.K.F., von Haeseler, A. & Jermiin, L.S. (2017) ModelFinder: fast model selection for accurate phylogenetic estimates. Nature Methods, 14, 587–589. https://doi.org/10.1038/nmeth.4285
  9. Katoh, K. & Standley, D.M. (2013) MAFFT Multiple Sequence Alignment Software version 7: improvements in performance and usability. Molecular Biology and Evolution, 30 (4), 772–780. https://doi.org/10.1093/molbev/mst010
  10. Lanfear, R., Frandsen, P.B., Wright, A.M., Senfeld, T. & Calcott, B. (2016) PartitionFinder 2: new methods for selecting partitioned models of evolution formolecular and morphological phylogenetic analyses. Molecular biology and evolution, 34 (3), 772–773. https://doi.org/10.1093/molbev/msw260
  11. Letunic, I. & Bork, P. (2024) Interactive Tree of Life (iTOL) v6: recent updates to the phylogenetic tree display and annotation tool, Nucleic Acids Research, gkae268. [published online] https://doi.org/10.1093/nar/gkae268
  12. McFadden, C.S. & van Ofwegen, L.P. (2013) A second, cryptic species of the soft coral genus I ncrustatus (Anthozoa: Octocorallia: Clavulariidae) from Tierra del Fuego, Argentina, revealed by DNA barcoding. Helgoland Marine Research, 67 (1), 137–147. https://doi.org/10.1007/s10152-012-0310-7
  13. McFadden, C.S., van Ofwegen, L.P. & Quattrini, A.M. (2022) Revisionary systematics of Octocorallia (Cnidaria: Anthozoa) guided by phylogenomics. Bulletin of the Society of Systematic Biologists, 1 (3), 8735. https://doi.org/10.18061/bssb.v1i3.8735
  14. Nguyen, L.T., Schmidt, H.A., von Haeseler, A. & Minh, B.Q. (2015) IQ-TREE: a fast and effective stochastic algorithm for estimating maximum-likelihood phylogenies. Molecular Biology and Evolution, 32, 268–274. https://doi.org/10.1093/molbev/msu300
  15. Nutting, C.C. (1908) Descriptions of the Alcyonaria collected by the U.S. Bureau of Fisheries steamer Albatross in the vicinity of the Hawaiian Islands in 1902. Proceedings of the United States National Museum, 34, 543–601, pls. 41–51. https://doi.org/10.5479/si.00963801.34-1624.543
  16. Pante, E. & Watling, L. (2012) Chrysogorgia from the New England and Corner Seamounts: Atlantic–Pacific connections. Journal of the Marine Biological Association of the United Kingdom, 92 (5), 911–927. https://doi.org/10.1017/S0025315411001354
  17. Ronquist, F., Teslenko, M., van der Mark, P., Ayres, D.L., Darling, A., Höhna, S., Larget, B., Liu, L., Suchard, M.A. & Huelsenbeck, J.P. (2012) MrBayes 3.2: efficient Bayesian phylogenetic inference and model choice across a large model space. Systematic Biology, 61, 539–542. https://doi.org/10.1093/sysbio/sys029
  18. Sánchez, J.A., Lasker, H.R. & Taylor, D.J. (2003) Phylogenetic analyses among octocorals (Cnidaria): mitochondrial and nuclear DNA sequences (lsu-rRNA, 16S and ssu-rRNA, 18S) support two convergent clades of branching gorgonians. Molecular Phylogenetics and Evolution, 29 (1), 31–42. https://doi.org/10.1016/S1055-7903(03)00090-3
  19. Tamura, K., Stecher, G. & Kumar, S. (2021) MEGA11: molecular evolutionary genetics analysis version 11. Molecular Biology and Evolution, 38 (7), 3022–3027. https://doi.org/10.1093/molbev/msab120
  20. Verrill, A.E. (1883) Report on the Anthozoa, and on some additional species dredged by the “Blake” in 1877–1879, and by the U.S. Fish Commission steamer “Fish Hawk” in 1880-82. Bulletin of the Museum of Comparative Zoology at Harvard College, 11, 1–72.
  21. Watling, L. (2007) A review of the genus Iridogorgia (Octocorallia: Chrysogorgiidae) and its relatives, chiefly from the North Atlantic Ocean. Journal of the Marine Biological Association of the UK, 87, 393–402. https://doi.org/10.1017/S002531540705535X
  22. Xiang, C., Gao, F., Jakovlic, I., Lei, H., Hu, Y., Zhang, H., Zou, H., Wang, G. & Zhang, D. (2023) Using PhyloSuite for molecular phylogeny and tree‐based analyses. iMeta, e87. https://doi.org/10.1002/imt2.87
  23. Xu, Y., Zhan, Z., Li, Y. & Xu, K. (2020) Morphology and phylogenetic analysis of two new species of deep-sea golden gorgonians (Cnidaria: Octocorallia: Chrysogorgiidae) from seamounts in the Western Pacific Ocean. Zootaxa, 4731 (2), 249–262. https://doi.org/10.11646/zootaxa.4731.2.4
  24. Xu, Y., Zhan, Z. & Xu, K. (2021) Morphological and molecular characterization of five species including three new species of golden gorgonians (Cnidaria: Octocorallia) from seamounts in the western Pacific. Biology, 10, 588. https://doi.org/10.3390/biology10070588
  25. Xu, Y., Zhan, Z. & Xu, K. (2023) Studies on western Pacific gorgonians (Anthozoa: Octocorallia, Chrysogorgiidae). Part 1: a review of the genus Chrysogorgia, with description of a new genus and three new species. Zootaxa, 5321 (1), 1–107. https://doi.org/10.11646/zootaxa.5321.1.1
  26. Zhang, D., Gao, F., Jakovlić, I., Zou, H., Zhang, J., Li, W. & Wang, G. (2020) PhyloSuite: An integrated and scalable desktop platform for streamlined molecular sequence data management and evolutionary phylogenetics studies. Molecular Ecology Resources, 20 (1), 348–355. https://doi.org/10.1111/1755-0998.13096

How to Cite

Xu, Y., Watling, L., Zhan, Z. & Xu, K. (2025) Studies on western Pacific gorgonians (Anthozoa: Octocorallia: Chrysogorgiidae). Part 2: unexpected diversity of the genus Iridogorgia in the tropical western Pacific with descriptions of two new species. Zootaxa, 5689 (3), 451–486. https://doi.org/10.11646/zootaxa.5689.3.3