Ecology, Morphology, Phylogeny and Taxonomic Revision of Giant Radiolarians, Orodaria ord. nov. (Radiolaria; Rhizaria; SAR)

Yasuhide Nakamura; Akihiro Tuji; Katsunori Kimoto; Atsushi Yamaguchi; Rie S Hori; Noritoshi Suzuki

doi:10.1016/j.protis.2021.125808

Ecology, Morphology, Phylogeny and Taxonomic Revision of Giant Radiolarians, Orodaria ord. nov. (Radiolaria; Rhizaria; SAR)

Protist. 2021 Jul;172(3):125808. doi: 10.1016/j.protis.2021.125808. Epub 2021 May 13.

Authors

Yasuhide Nakamura¹, Akihiro Tuji², Katsunori Kimoto³, Atsushi Yamaguchi⁴, Rie S Hori⁵, Noritoshi Suzuki⁶

Affiliations

¹ Estuary Research Center, Shimane University, 1060, Nishikawatsu-cho, Matsue 690-8504, Japan; Department of Botany, National Museum of Nature and Science, 4-1-1, Amakubo, Tsukuba 305-0005, Japan. Electronic address: jasnakamura@gmail.com.
² Department of Botany, National Museum of Nature and Science, 4-1-1, Amakubo, Tsukuba 305-0005, Japan.
³ Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15, Natsushima-cho, Yokosuka 237-0061, Japan.
⁴ Plankton Laboratory, Graduate School of Fisheries Sciences, Hokkaido University, 3-1-1, Minato-cho, Hakodate 041-8611, Japan.
⁵ Department of Earth Sciences, Graduate School of Science and Engineering, Ehime University, 3, Bunkyo-cho, Matsuyama 790-8577, Japan.
⁶ Department of Earth Science, Graduate School of Science, Tohoku University, 6-3, Aramaki Aoba, Aoba-ku, Sendai 980-8578, Japan.

PMID: 34186475
DOI: 10.1016/j.protis.2021.125808

Abstract

The phylogenetic affiliation of Oroscenidae, a family of Radiolaria possessing large siliceous skeletons, was thoroughly revised in this study. Plankton sampling was conducted over seven years in seven sea areas of the Northern Hemisphere. Molecular analyses on the obtained specimens revealed that living oroscenids are phylogenetically different from hitherto-known radiolarian orders. The detailed examinations by Microfocus X-ray Computed Tomography and Scanning Electron Microscopy clarified that oroscenids and the related family (Thalassothamnidae) have unique skeletal characteristics different from other radiolarian orders. Judging from their phylogenetic distinctiveness and the difference in the morphology and ecology, Oroscenidae and Thalassothamnidae should be classified in a single order distinct from other radiolarian orders, and consequently, a new order, Orodaria, is established.

Keywords: MXCT; shell-bearing protist; silica; single-cell PCR; unicellular zooplankton.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Microscopy, Electron, Scanning
Phylogeny
Rhizaria*