Circularius wilsoni (Thomson, 1921) Mcfadden & Van Ofwegen, 2017

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), pp. 451-488 : 470-471

publication ID	https://doi.org/ 10.11646/zootaxa.4363.4.1
publication LSID	lsid:zoobank.org:pub:86DE1B94-63AE-4ABF-B28A-0ECEA22D2F10
DOI	https://doi.org/10.5281/zenodo.5613942
persistent identifier	https://treatment.plazi.org/id/038A0776-6C19-286E-FF24-5B5FFDA94DE6
treatment provided by	Plazi
scientific name	Circularius wilsoni (Thomson, 1921)
status	comb. nov.

Treatment

Circularius wilsoni (Thomson, 1921) , n. comb.

Fig. 5e View FIGURE 5 , 10–11 View FIGURE 10 View FIGURE 11

Alcyonium (Erythropodium) Wilsoni Thomson, 1921: 160 –162; Thomson, 1923: 50.

Parerythropodium Wilsoni Tixier-Durivault, 1954a: 265 .

Alcyonium wilsoni Williams, 1992a: 298 –300; 1992b: 381, 396, fig. 21E.

Material examined. CASIZ 222396 (SAF446), RMNH Coel. 40208 (SAF447), RMNH Coel. 40207 (SAF448), SAM ( SAF449 View Materials ), SAF456, South Africa, Western Cape, Cape Peninsula, Star Walls , 34º02.472'S, 18º18.083'E, depth 20–29 m, coll. C.S. McFadden, 24 March 2008 GoogleMaps . UF3876, South Africa, Western Cape, Capetown, Hout Bay / Vulcan Rock , depth 24 m, coll. J. Starmer, 0 1 April 2000 .

Remarks. Williams (1992a) provides a good description of this species. Similar to the material he examined, the colonies we collected were growing on the surfaces of other organisms, specifically mussels and polychaete tubes ( Fig. 5e View FIGURE 5 ). Small colonies, most <5 mm in diameter, occur in aggregations of 20 or more, typically separated from one another by a few mm to 1 cm. These aggregations appear to arise as the result of colony fission and the subsequent movement of clonemates away from each other, as has been documented in Discophyton rudyi (Verseveldt & Ofwegen) (McFadden 1991) . In a few cases adjacent colonies are still connected by a thin membrane, but in most this connection has been lost and the intervening substrate has been overgrown by sponges or other encrusting organisms. Williams (1992a) included few SEM images of the sclerites of this species, so we include additional images here to facilitate comparisons with similar species ( Figs. 10–11 View FIGURE 10 View FIGURE 11 ). We also note that in life colonies are pink, but they fade to cream, white or beige in ethanol; the sclerites are colorless.

Superficially, C. wilsoni n. comb. resembles the pink color morph of Tenerodus fallax n. comb., but it can be distinguished from that species in the field by its habit of forming aggregations of very small colonies ( Fig. 5e View FIGURE 5 ). C. wilsoni can be further distinguished from T. fallax by the sclerites, which are predominantly spindles and clubs ( Figs. 10–11 View FIGURE 10 View FIGURE 11 ) rather than tuberculate spheroids ( Figs. 15–16 View FIGURE 15 View FIGURE 16 ). Although Williams (1992a) speculated that Alcyonium wilsoni might represent a variant of Alcyonium fauri (= T. fallax n. comb.), the marked difference in sclerite form between the species and molecular phylogenetic analyses ( Fig. 1 View FIGURE 1 ) both confirm that they are clearly different species. Phylogenetic analyses suggest that C. wilsoni n. comb. is closely related to Leptophyton . That genus does not have sclerites arranged as a collaret and points in the polyps, however, and the colonies are typically much larger and have branched lobes.