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Circularius

Circularius

Mcfadden & Van Ofwegen, 2017

GBIF:137679941

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Descriptions(4)

Diagnosis. Colonies lobate, lobes often arising from encrusting, membranous base. Polyps retractile. Sclerites predominantly spindles and clubs. Some radiates may be present in base of colony. Polyps with spindles arranged to form collaret and points. Small rods in tentacles. Interior of colony with same sclerite types as surface. Sclerites colorless.
Mcfadden, Catherine S., Van Ofwegen, Leen P. (2017): Revisionary systematics of the endemic soft coral fauna (Octocorallia: Alcyonacea: Alcyoniina) of the Agulhas Bioregion, South Africa. Zootaxa 4363 (4): 451-488, DOI: 10.11646/zootaxa.4363.4.1
Remarks. Circularius n. gen. is distinguished from other genera in family Leptophytidae by the arrangement of sclerites in the polyps, which form a collaret and points. Species in the genera Alcyonium (Alcyoniidae) and Gersemia (Nephtheidae) also have a collaret and points. Gersemia, however, lacks clubs, and has predominantly radiates in the colony surface and few or no sclerites in the colony interior. Alcyonium has the coenenchymal sclerites arranged in two distinct layers. In contrast, in Circularius n. gen. the same sclerite types occur throughout the polyps, surface and interior of the colony. The growth form of Circularius n. gen. superficially resembles that of the northern hemisphere genus Discophyton McFadden & Hochberg, but in that genus the polyps lack sclerites and the coenenchymal sclerites are large, irregular forms. Molecular analyses place Circularius n. gen. in a clade with other genera endemic to South Africa, and sister to Leptophyton (Fig. 1).
Mcfadden, Catherine S., Van Ofwegen, Leen P. (2017): Revisionary systematics of the endemic soft coral fauna (Octocorallia: Alcyonacea: Alcyoniina) of the Agulhas Bioregion, South Africa. Zootaxa 4363 (4): 451-488, DOI: 10.11646/zootaxa.4363.4.1
Etymology. From the Latin circulor meaning to gather a group around oneself, in reference to the species’ tendency to occur as aggregations of small colonies. Gender: masc.
Mcfadden, Catherine S., Van Ofwegen, Leen P. (2017): Revisionary systematics of the endemic soft coral fauna (Octocorallia: Alcyonacea: Alcyoniina) of the Agulhas Bioregion, South Africa. Zootaxa 4363 (4): 451-488, DOI: 10.11646/zootaxa.4363.4.1
Type species. Alcyonium wilsoni Thomson, 1921 by original designation
Mcfadden, Catherine S., Van Ofwegen, Leen P. (2017): Revisionary systematics of the endemic soft coral fauna (Octocorallia: Alcyonacea: Alcyoniina) of the Agulhas Bioregion, South Africa. Zootaxa 4363 (4): 451-488, DOI: 10.11646/zootaxa.4363.4.1

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FIGURE 1. Maximum likelihood phylogeny of Octocorallia based on combined, partitioned analysis of 28S rDNA, COI and 16S mtDNA.South African species and clades are identified in blue. Filled circles indicate nodes with>70% bootstrap support and Bayesian posterior probabilities>0.95 (shown for South African clades only). Strongly supported clades (bootstrap 70%) with no South African members have been collapsed to facilitate readability. Phylogenetic position of Protodendron repens indicated with *.

Imageimage/png© Mcfadden, Catherine S.;Van Ofwegen, Leen P.Mcfadden, Catherine S.;Van Ofwegen, Leen P.

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Revisionary systematics of the endemic soft coral fauna (Octocorallia: Alcyonacea: Alcyoniina) of the Agulhas Bioregion, South Africa

checklist

This dataset contains the digitized treatments in Plazi based on the original journal article Mcfadden, Catherine S., Van Ofwegen, Leen P. (2017): Revisionary systematics of the endemic soft coral fauna (Octocorallia: Alcyonacea: Alcyoniina) of the Agulhas Bioregion, South Africa. Zootaxa 4363 (4): 451-488, DOI: 10.11646/zootaxa.4363.4.1

Abstract

The Agulhas Bioregion of southern South Africa supports a unique octocoral fauna that is entirely endemic to the region. Recent molecular phylogenetic studies indicate that this endemism extends to deeper taxonomic levels than had previously been recognized, and that most of these endemic species belong to genera and families that are also endemic to South Africa. Here we revise the taxonomy of soft corals (subordinal group Alcyoniina) that were previously assigned to the cosmopolitan families Alcyoniidae, Nephtheidae and Nidaliidae, describing three new families endemic to South Africa, along with four new genera and four new species. We reassign the endemic genera Acrophytum, Pieterfaurea and Lampophyton to Acrophytidae n. fam, and describe a new species of Lampophyton, L. spinatum n. sp. The endemic species Protodendron bruuni is reassigned to a new, monotypic genus, Corymbophyton bruuni n. comb., and family, Corymbophytidae n. fam. The endemic genus Leptophyton is placed in a third new family, Leptophytidae n. fam., along with three new genera that are established for species previously assigned to Alcyonium: Circularius wilsoni n. comb., Porphyrophyton distinctum n. comb., and Tenerodus fallax n. comb. In addition, we describe new species of Leptophyton, L. fustis n. sp.; Tenerodus, T. pollex n. gen. n. sp.; and Alcyonium, A. dolium n. sp.; reassign Protodendron verseveldti to Tenerodus verseveldti n. comb.; and reassign the endemic genus Dimorphophyton to family Paralcyoniidae. Although molecular phylogenetic analyses unite Acrophytidae, Corymbophytidae and Leptophytidae within a well-supported monophyletic group, both morphological and molecular distinctions support maintaining them as three separate families. These revisions increase the number of endemic species of shallow-water soft corals known from the Agulhas Bioregion to 40, and the number of endemic genera to 13.

Key words: molecular phylogenetics, Acrophytum, Alcyonium, Dimorphophyton, Lampophyton, Leptophyton, Pieterfaurea, Protodendron

Mcfadden C S, Van Ofwegen L P, plazi (2017). Revisionary systematics of the endemic soft coral fauna (Octocorallia: Alcyonacea: Alcyoniina) of the Agulhas Bioregion, South Africa. Plazi.org taxonomic treatments database. Checklist dataset https://doi.org/10.11646/zootaxa.4363.4.1 accessed via GBIF.org on 2026-06-16.

CC0Published 12/13/2017View dataset
GBIF Usage Key
137679941
Dataset Key
a141fa76-cc88-4901-944a-306171e41413
Origin
source
Backbone Key
9420407
Taxon ID
038A07766C182869FF245CEEFC6848F8.taxon
Last Crawled
6/10/2026
Last Interpreted
6/10/2026