Leptophyton fustis, 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 : 473-475

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.5613950
persistent identifier	https://treatment.plazi.org/id/038A0776-6C1C-2862-FF24-5D06FE334B22
treatment provided by	Plazi
scientific name	Leptophyton fustis
status	sp. nov.

Treatment

Leptophyton fustis n. sp.

Figs. 5d View FIGURE 5 , 13a View FIGURE 13 , 14 View FIGURE 14

Material examined. Holotype. RMNH Coel. 40211 (SAF087), South Africa, Eastern Cape, Algoa Bay , Riy Banks , 33º59.097’S, 25º51.774’E, depth 15–20 m, coll. C.S. McFadden, 11 March 2008 GoogleMaps . Paratypes. RMNH Coel. 40213 (SAF086) , RMNH Coel. 40212 (SAF088), same data as holotype GoogleMaps . Other material. SAF099, same data as holotype except 33º59.069’S, 25º51.841E. UF2435, South Africa, Plettenberg Bay , Grootbank, depth 9 m, coll. J. Starmer, 22 March 2000 GoogleMaps .

Description. The holotype is an erect lobate colony 5.7 cm in height, with a poorly demarcated stalk approximately 2.5 cm long and 1.0 cm in diameter ( Fig. 13a View FIGURE 13 ). It is a fragment of a larger colony ( Fig. 5d View FIGURE 5 ). The surface of the stalk is slightly rough, with numerous longitudinal creases and bumps formed by denser aggregations of sclerites. Four elongate, primary lobes, 0.5–2.7 cm in length and 0.5–1.0 cm in diameter, arise from the stalk; the larger lobes branch to give rise to a few smaller lobes. The polyps are distributed uniformly over the surfaces of the lobes. Polyps are retractile, although in the holotype a majority were preserved with the tentacles extended or in various stages of incomplete retraction. The colony has a flabby consistency, and the surface tissue is thin and easily torn.

The polyps have small spindles and rods, 0.07–0.16 mm long, in the tentacles ( Fig. 14a View FIGURE 14 ). Around the bases of the polyps and in the surface of the polyparium and stalk are radiates, 0.08–0.15 mm long ( Fig. 14b View FIGURE 14 ), and stout club-like sclerites, 0.11–0.18 mm long ( Fig. 14c View FIGURE 14 ). The surface of the stalk base has predominantly small radiates, 0.05–0.09 mm long ( Fig. 14d View FIGURE 14 ). The interior of the colony lacks sclerites.

All three paratypes are smaller colonies or portions of colonies, 2.5 cm tall with the stalk constituting about half of the total height. They have from 1–3 primary lobes, each subdivided into a few secondary lobes. In all other respects they resemble the holotype. Spherical gametes, 0.25–0.55 mm in diameter, can be seen within the stalk of RMNH Coel. 40212 and SAF099.

Color. In life, pale orange to salmon-pink ( Fig. 5d View FIGURE 5 ). White or cream in alcohol. Sclerites colorless.

Etymology. From the Latin fustis , a club or cudgel, in reference to the stout, club-shaped sclerites that surround the base of the polyp.

Remarks. Although L. fustis n. sp. and L. benayahui share a similar colony growth form, weakly armored polyps, and both lack sclerites in the colony interior, the form of the sclerites differs greatly between the two congeners ( Figs. 12 View FIGURE 12 , 14 View FIGURE 14 ). At present, their geographic ranges are not known to overlap, with L. benayahui found in the subtropical regions of KwaZulu-Natal and L. fustis n. sp. in the cold waters of the Eastern Cape (Algoa and Plettenberg Bays). Superficially, expanded colonies of L. fustis n. sp. resemble the pink color morph of Tenerodus fallax n. comb. (compare Figs. 5d and 5g View FIGURE 5 ) with which it may co-occur. The form and arrangement of sclerites in the two species differ greatly, however. The heavily armored polyps and surface of T. fallax give the contracted or preserved colony a firm consistency. In contrast, L. fustis n. sp. lacks sclerites in the colony interior and has smaller, more sparsely arranged sclerites in the colony surface, giving the colonies a weak, flabby consistency. L. fustis can be distinguished from Gersemia liltvedi by its fully retractile polyps that are distributed over the entire surface of the branched lobes rather than being restricted to terminal catkins. L. benayahui and L. fustis n. sp. differed at all of the loci we sequenced, with pairwise genetic distances of 2.6% at 28S rDNA, 5.4–6.0% at COI and 2.1–2.5% at 16S rDNA.