Tenerodus pollex, 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 : 479-482

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.5613964
persistent identifier	https://treatment.plazi.org/id/038A0776-6C16-2865-FF24-5B2EFE334DAE
treatment provided by	Plazi
scientific name	Tenerodus pollex
status	sp. nov.

Treatment

Tenerodus pollex n. sp.

Figs. 5f View FIGURE 5 , 13d View FIGURE 13 , 17–18 View FIGURE 17 View FIGURE 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 GoogleMaps . Paratypes. RMNH Coel. 40221 (SAF417) , RMNH Coel. 40220 (SAF418), same data as holotype GoogleMaps . Other material. SAF419, same data as holotype GoogleMaps .

Description. The holotype consists of three small, digitate lobes that may originally have been attached at the base but are now separated ( Fig. 13d View FIGURE 13 ). 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 View FIGURE 17 ). 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 View FIGURE 17 ). At the base of the stalk the same sclerite forms are present only slightly smaller, 0.09–0.17 mm long ( Fig. 18 View FIGURE 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 View FIGURE 5 ). 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 View FIGURE 13 , 14C View FIGURE 14 ) closely resemble T. pollex n. sp. In addition, some of the very irregular sclerite forms depicted in his Fig. 14D View FIGURE 14 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 View FIGURE 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.