Tenerodus fallax

Alcyonium fallax Lüttschwager, 1922 (nom. nov.): 520, 534; Lüttschwager, 1926: 288. Alcyonium fauri (non Thomson, 1910) Broch, 1939: 8 – 11; Williams, 1992 a (part): 277 – 282, fig. 1 B; 1992 b: 381 – 385, 396, fig. 20 G; Branch et al. 2010: 38, fig. 12.8.

Description. As re-described by Williams (1992 a), Alcyonium fauri Thomson sensu lato encompasses material with a wide range of colony growth forms (“ membranous, globular to capitate, or lobate ”), colors (“ purple, pink, white, golden yellow, orange, or dark smoke-grey to dark brown ”), and polyp armature (polyp sclerites ranging from dense to very sparse or absent). We consider it likely that multiple species have been lumped within this broad definition of this taxon. Here we re-describe newly collected material that matches the original description of Alcyonium purpureum Hickson (= Alcyonium fallax Lüttschwager) and Thomson’s (1910) later more detailed description of that species. Some of our material was collected from a site very close to the type locality in Mossel Bay. T. fallax n. comb. forms encrusting to lobate colonies in which the polyps arise from a membranous base and are fused together along their lengths to form a more-or-less homogeneous mass (Fig. 13 b, c). The polyps are prominent, and remain oriented vertically with their oral surfaces facing upwards, even when retracted. There is little colony coenenchyme between neighboring polyps, with the result that in those polyps that are located on the periphery of the colony the entire length of the polyp body remains visible and distinguishable from its neighbors. When fully retracted the polyps remain visible as coenenchymal mounds. Colonies range from encrusting, a few mm thick, to erect forms> 3 cm tall with multiple lobes. They often grow attached to other organisms such as worm tubes or bivalve shells. The polyp sclerites are robust spindles and slightly clubbed forms, 0.16 – 0.25 mm long, with complex tubercles (Fig. 15 a), and torch-like clubs, 0.13 – 0.22 mm long, with asymmetrical heads of smooth, spinose processes (Fig. 15 b). They are arranged in eight longitudinal tracts in the base of the polyp and extend distally to form points at the bases of the tentacles. A collaret of transverse sclerites is lacking. The tentacles have smooth, flat, antler-like rods, 0.12 – 0.18 mm long (Fig. 15 c). In the surface of the polyparium and base of the colony there are radiates, 0.06 – 0.11 mm long, and tuberculate spheroids, 0.08 – 0.13 mm long (Fig. 15 d), in addition to the same types of spindles and clubs found in the polyps. As one moves from the base of a polyp to the base of the colony the proportion of sclerite types shifts gradually from predominantly spindles and clubs to predominantly radiates and spheroids, but there is no sharp demarcation in sclerite form between different anatomical regions. The colony interior contains mostly spheres and radiates of the same sizes and shapes as those found in the surface of the base (Fig. 16). Color. In life, vivid purple, yellow, pink, or white with purple or yellow highlights (Fig. 5 g, h). All colors turn brown to cream in EtOH. Sclerites colorless.

Remarks. Hickson (1904) first described Alcyonium purpureum non Lamarck, a bright purple colony collected from the jetty at Mossel Bay. Thomson (1910) subsequently identified this same species in his material. Thomson’s description and illustration of A. purpureum Hickson best matches the specimens described here: colonies consisting of a number of lobes arising from an encrusting membrane; sclerite forms are mostly clubs, spindles, tuberculate spheres and " double spheres ", similar in all parts of the colony; spindles arranged in eight parallel bands and irregularly en chevron in the polyps; some radiates (“ double clubs ”) in the colony base; color in life due to a soluble purple pigment. From this description we conclude that our material corresponds to Thomson’s A. purpureum Hickson. Lüttschwager (1922) recognized that the name A. purpureum used by Hickson was preoccupied by a species from Australia (A. purpureum Linnaeus), and re-named the South African species Alcyonium fallax nom. nov. In the same paper in which he identified purple, lobate colonies as A. purpureum Hickson, Thomson (1910) described Alcyonium fauri, a brown, encrusting colony that lacks sclerites in the polyps and colony interior, and has only “ double wheels ” in the colony surface. From his illustrations these sclerites appear to be compact radiates or spheroids with sparse ornamentation and a median waist. Based on examination of material collected by Carlgren (and apparently not the material of Thomson), Broch (1939) concluded that there was wide variation in the degree of polyp armature and presence of interior sclerites among specimens, and consequently synonymized A. fauri with A. fallax, the former name taking precedence. Williams (1992 a) accepted Broch’s conclusion that A. fauri and A. purpureum Hickson (= A. fallax Lüttschwager) are synonyms, but he also does not appear to have examined the material of Thomson. Thomson's original material was also unavailable to us for examination, but based on his illustrations and detailed descriptions, we disagree that these two forms are synonymous, and retain the species name fallax for material that fits the description given above. Thomson’s (1910) description of A. fauri does not closely match any species recorded subsequently from South Africa with the possible exception of Porphyrophyton distinctum n. comb. (see remarks above for that species). Although Williams (1992 a) illustrated the range of variation in polyp armature and sclerite form he observed among three colonies he examined, he did not indicate which specimens were illustrated or which sclerite variants came from which colony. The absence of such information makes it impossible to determine if any of the specimens he included within A. fauri sensu lato match those we recognize here as different species. The colony forms he illustrates in Figs. 1 B, 13 B, and 13 E, and the polyp armature depicted in Fig. 14 A most closely match T. fallax n. comb.

Material examined. RMNH Coel. 40218 (SAF 013), CASIZ 222381 (SAF 014), SAF 015, South Africa, Western Cape, Mossel Bay, Phluffy Reef, 34 º 10.988 ' S, 22 º 09.745 ' E, depth 12 – 15 m, coll. C. S. McFadden, 0 8 March 2008. RMNH Coel. 40216 (SAF 059), RMNH Coel. 40215 (SAF 067), South Africa, Eastern Cape, Port Elizabeth, Algoa Bay, Bell Buoy 1, 33 º 58.927 ’ S, 25 º 41.473 ’ E, depth 20 m, coll. C. S. McFadden, 10 March 2008. RMNH Coel. 40214 (SAF 072), CASIZ 222384 (SAF 073), SAF 084, South Africa, Eastern Cape, Port Elizabeth, Algoa Bay, Philips Reef, 33 º 15.933 ' S, 25 º 41.768 ' E, depth 10 – 12 m, coll. C. S. McFadden, 10 March 2008. SAF 098, South Africa, Eastern Cape, Port Elizabeth, Algoa Bay, Riy Banks, 33 º 59.069 ' S, 25 º 51.841 ' E, depth 14 – 17 m, coll. C. S. McFadden, 11 March 2008. RMNH Coel. 40217 (SAF 383), SAF 384, CASIZ 222395 (SAF 386), South Africa, Western Cape, Cape Peninsula, Vulcan Rock, 34 º 03.970 ' S, 18 º 18.627 ' E, depth 15 – 27 m, coll. C. S. McFadden, 23 March 2008.