Litophyton cockburnensis Van 2020, sp. nov.
Creators: name: Van Ofwegen, Leen P.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Cnidaria
Anthozoa
Alcyonacea
Nephtheidae
Litophyton
Litophyton cockburnensis

description: Litophyton cockburnensis sp. nov.
(Figs. 1a, 2a, 3)
Material examined. Holotype NTM C10288, Great Barrier Reef, GBR 2, Cockburn reef, depth 12-15 m, 10 December 1990, coll. J. Jan; paratype: NTM C10322, Great Barrier Reef, GBR 3, Nomad/Mason reef, depth 3-6 m, 11 December 1990, coll. J. Jan.
Description. The holotype NTM C10288 is 11.5 cm high and 9.5 cm wide, the stalk is 2.5 cm high (Fig. 1a). The polyps are up to 0.7 mm wide and 0.8 mm high and grouped in long catkins.
Polyps. With very irregular arrangement of sclerites in eight points (Fig. 2a). Abaxial and lateral point sclerites are spindles with simple tubercles and spiny distal part, largest present abaxially, up to 0.45 mm long (Fig. 3a); towards the adaxial side they become smaller (Fig. 3b). Tentacles with curved scales up to 0.10 mm long (Fig. 3c). Adaxial side of the polyp stalk with many straight rods, up to 0.10 mm long (Fig. 3d). Supporting bundle composed of one or two spindles up to 1.50 mm long, with simple tubercles and a spiny tip projecting for a maximum distance of 0.30 mm (Fig. 3e). Some polyp sclerites have an optically black inner core. Many xeniid type sclerites are present in the polyp body (Figs. 2a, the small ovals in the polyp, 3f).
Surface layer top stalk. Spindles, some unilaterally spinose, up to 1 mm long and all with simple tubercles (Fig. 3g).
Surface layer base stalk. Capstans and spiny derivatives of capstans up to 0.20 mm long, and spindles, mostly unilaterally spinose, up to 0.70 mm long, with complex tubercles (Fig. 3h).
Interior stalk. Spindles with complex tubercles (Fig. 3i) and pointed ends. These spindles are mostly up to 0.75 mm long, a few are longer than 1 mm (Fig. 3j). Smaller spindles are somewhat flattened (Fig. 3k).
Etymology. Named after the type locality.
Distribution. Great Barrier Reef: Cockburn reef, Nomad/Mason reef.
Remarks. This is the only Australian Litophyton species with projecting supporting bundles and polyps higher than wide. Some polyps of L. elfordensis sp. nov. are also higher than wide (Fig. 2e, h) but most are wider than high (Fig. 2d, f-g).
Both holotype and paratype have xeniid type sclerites in the polyps (Figs. 2a, 3f). This is also the case in some specimens of L. spinulosum sp. nov., but that species has a clearly different colony shape, with spherical catkins (Fig. 26 a-c), and the tubercles on its sclerites are more complex (Figs. 26 d-i, 27-30).
L. robustum (Kükenthal, 1895) (Ternate, Indonesia) resembles this species regarding polyps being higher than wide (Fig. 4a). However, L. robustum has much larger spindles in the interior of the base of the stalk, up to 1.5 mm long. For comparison the colony (Fig. 12d) and sclerites (Fig. 4) of L. robustum are also presented.
description: Published as part of Van Ofwegen, Leen P., 2020, The genus Litophyton Forskål, 1775 (Octocorallia: Alcyonacea: Nephtheidae) from Australia, pp. 1-131 in Zootaxa 4764 (1) on page 6, DOI: 10.11646/zootaxa.4764.1.1, http://zenodo.org/record/3764923