Lampophyton spinatum

Remarks. L. spinatum n. sp. is distinguished from L. planiceps by the presence of large spindles in the polyparium. These sclerites are arranged longitudinally around the polyps, and the ends of some protrude from the polyparium surface and around the margins of the stalk (Fig. 3 a – e). In contrast, L. planiceps lacks sclerites in the polyparium, and no or very few sclerites protrude from the surface of the stalk (Fig. 3 f, g). The form of the spindles in the stalk is the same in the two species, but those of L. planiceps are on average longer and narrower (to 0.2 mm wide) (Fig. 6). Williams (1986 a) states that the polyparium of L. planiceps lacks sclerites “ except in two specimens collected from eastern Cape ” (SAM H- 3713). It is likely, therefore, that the material he examined included individuals of both species, but his specimens were not available to us for examination. Whereas the polyparium of L. planiceps can be retracted completely, with the distal end of the stalk folding over to enclose the polyparium within, L. spinatum n. sp. appears to be incapable of such retraction. All of the preserved specimens retain a vaseshaped form, and, although the polyps are fully or partially retracted, the surface of the polyparium remains visible and the distal margins of the stalk are not folded over it, as they are in the majority of L. planiceps specimens (Fig. 3 f, g). The morphological distinctions among these two very similar species are supported by molecular phylogenetic data. Individuals that have large sclerites protruding from the polyparium (L. spinatum n. sp.) differ from those that lack sclerites in the polyparium (L. planiceps) at each of the loci we sequenced. Pairwise genetic distances (K 2 p) between the two species were 2.3 % at mtMutS, 1.0 % at COI and 1.6 % at 28 S rDNA, all values greater than those typical of intraspecific differences in octocorals (McFadden et al. 2011, 2014).

Etymology. From the Latin spinatus, crowned with thorns, denoting the large spindles that protrude through the surface of the polyparium.

Material examined. Holotype. RMNH Coel. 40198 (SAF 164), South Africa, Eastern Cape, Algoa Bay, White Sands 15; 33 º 59.900 ' S, 25 º 42.522 ' E, 14 – 16 m, coll. C. S. McFadden, 12 March 2008. Paratypes. RMNH Coel. 40199 (SAF 195), South Africa, Algoa Bay, White Sands 6; 34 º 00.368 ' S, 25 º 43.166 ' E, depth 21 – 25 m, coll. B. Picton, 12 March 2008. CASIZ 222392, same as RMNH Coel. 40199. Other material. SAF 125, South Africa, Eastern Cape, 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. Lampophyton planiceps: CASIZ 222386 (SAF 136), SAF 137, South Africa, Eastern Cape, Algoa Bay, White Sands 6; 34 º 00.368 ' S, 25 º 43.166 ' E, depth 21 – 25 m, coll. B. Picton, 12 March 2008. RMNH Coel. 40200, RMNH Coel. 40201, CASIZ 222393, South Africa, Eastern Cape, Algoa Bay, Evans Peak, 33 º 50.578 ' S, 25 º 48.988 ' E, depth 22 – 28 m, coll. C. S. McFadden, 14 March 2008. The holotype is an unbranched colony 2.8 cm tall, with a distinct stalk and retractile polyps (Fig. 3 a). Approximately one-half of the upper region of the stalk and a portion of the polyparium have been removed for DNA analysis. The stalk is 0.6 cm in diameter near its base, but flares to 0.9 cm at the distal end. The stalk surface is rough with numerous longitudinal furrows and transverse wrinkles. Large sclerites can be seen on the stalk surface and protruding from the base. Numerous large spindles also protrude from the margin of the stalk, surrounding the polyparium (Fig. 3 b). The polyparium is withdrawn within the stalk, with only the dome-shaped surface, with 8 – 10 large polyps in various stages of retraction, visible. Additional large spindles protrude from the surface of the polyparium, extending from the coenenchymal space between the polyps (Fig. 3 b). The polyps themselves are devoid of sclerites. The sclerites of the polyparium are large, fat spindles, 1.0 – 1.4 mm long and up to 0.25 mm wide, with complex tubercles (Fig. 4 a, d). The lower region of the stalk includes similar spindles up to 2.3 mm long, as well as needlelike forms, 1.1 – 1.75 mm long (Fig. 4 b), and rather smooth rods to 0.45 mm long (Fig. 4 c). Paratypes and other material: SAF 125 is a 1.8 cm tall colony, with a stalk that is 0.4 cm in diameter at its base and flares to 1.0 cm at the distal end (Fig. 3 c). The dome-shaped polyparium has about 25 polyps, most of which are fully retracted. Large sclerites protrude at various angles from the upper part of the stalk and vertically from the surface of the polyparium between the polyps (Fig. 3 d, e). RMNH Coel. 40199 (SAF 195) and CASIZ 222392 are similar in appearance but 2.6 cm tall. In other respects the paratypes resemble the holotype. Color. In life, polyparium yellow with purple polyps (Fig. 5 a). Brown in ethanol.