Tenerodus pollex Mcfadden & Van Ofwegen 2017, n. sp.
Creators: name: Mcfadden, Catherine S.
name: Van Ofwegen, Leen P.
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Cnidaria
Anthozoa
Alcyonacea
Paralcyoniidae
Tenerodus
Tenerodus pollex

description: Tenerodus pollex n. sp.
Figs. 5f, 13d, 17–18
? Alcyonium fauri (non Thomson, 1910) Broch, 1939: 11 (part); Williams 1992a: fig. 13C, 14C.
Material examined. Holotype. RMNH Coel. 40219 (SAF420), South Africa, Western Cape, Cape Peninsula, Oudekraal, Justin’s Caves, 33º58.899'S, 18º21.590'E, depth 7–11 m, coll. C.S. McFadden, 24 March 2008. Paratypes. RMNH Coel. 40221 (SAF417), RMNH Coel. 40220 (SAF418), same data as holotype. Other material. SAF419, same data as holotype.
Description. The holotype consists of three small, digitate lobes that may originally have been attached at the base but are now separated (Fig. 13d). The largest of the three is 2.4 cm tall and 1.0 cm in diameter, with a stalk of 1.0 cm. The smallest lobe is 2.1 cm tall and 0.8 cm in diameter, and has had approximately half the polyparium removed for DNA analysis. The stalk and polyparium are demarcated only by the presence of polyps in the latter, and by a slight difference in color, with the polyparium darker than the stalk. The stalk is somewhat rough in appearance and has a number of longitudinal and transverse wrinkles. When fully retracted the polyps are visible as small mounds on the colony surface.
The polyps are devoid of sclerites except for a few small rods, 0.10–0.13 mm long, found in the tentacles (Fig. 17a). The sclerites of the surface of the polyparium and stalk are club-like forms, irregular ovals and radiates, 0.13– 0.20 mm long and up to 0.10 mm wide, all densely ornamented with complex tubercles (Fig. 17b, c). At the base of the stalk the same sclerite forms are present only slightly smaller, 0.09–0.17 mm long (Fig. 18). The interior of the colony has the same sclerite forms as the surface.
The two paratypes and SAF419 are similar, small digitate colonies to 2.5 cm tall. Both paratypes consist of a single small lobe and two lobes that may have been separated from a common base. In SAF419 three lobes remain attached via a common stalk. In all other respects the paratypes and SAF419 resemble the holotype.
Color. In life orange-brown (Fig. 5f). In alcohol, brown with darker brown polyps. Sclerites colorless or white.
Etymology. From the Latin pollex, thumb or big toe, in reference to the shapes of the contracted lobes.
Remarks. Broch (1939) discussed a specimen from Table Bay, Cape Peninsula that he considered to be a close match to Thomson’s (1910) description of Alcyonium fauri. He described it as brown in color with darker brown polyps and white sclerites that in places gave the colony surface “a chalky appearance,” an effect we also see in the holotype of T. pollex n. sp. Broch’s specimen lacked sclerites in the polyps, and in addition to the “double-wheels” depicted by Thomson (1910) it also had club-like sclerites in the upper part of the colony; Broch’s sketch of this sclerite type quite closely resembles the broad, triangular club-like forms we see in T. pollex n. sp. Williams (1992a) included a brown color morph within A. fauri sensu lato, and several of his illustrations of variants of that species (e.g., Figs. 13C, 14C) closely resemble T. pollex n. sp. In addition, some of the very irregular sclerite forms depicted in his Fig. 14D more closely resemble those found in T. pollex n. sp. than the spheroids and radiates typical of T. fallax n. comb. T. fallax n. comb. and T. pollex n. sp. differ from one another by pairwise genetic distances of 1.7–1.8% at 28S rDNA, 13.4–16.0% at COI, and 8.6–10.4% at 16S. Although the phylogenetic analysis suggests that T. pollex n. sp. is sister to [Circularius n. gen. + Leptophyton] (Fig. 1), support for that relationship is relatively weak, and we consider its morphological similarity to T. fallax n. comb. sufficient to place them in the same genus.
description: Published as part of 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, pp. 451-488 in Zootaxa 4363 (4) on pages 479-482, DOI: 10.11646/zootaxa.4363.4.1, http://zenodo.org/record/1114473