Litophyton laevis ( Kuekenthal , 1913)

van Ofwegen, Leen P., 2016, The genus Litophyton Forskal, 1775 (Octocorallia, Alcyonacea, Nephtheidae) in the Red Sea and the western Indian Ocean, ZooKeys 567, pp. 1-128 : 12-13

Taxon classification Animalia Alcyonacea Nephtheidae

Litophyton laevis ( Kuekenthal, 1913) Figures 2A, 36, 37, 38, 39, 40, 41

Nephthya laevis Kükenthal, 1913: 20, figs 9-13, pl. 2 fig. 5 (Red Sea, Jeddah).

Nephthea laevis ; Roxas 1933: 415; Verseveldt 1970: 219, figs 5-6, pl. 3 fig. 1 (Gulf of Suez, Et Tur).

Litophyton laevis Not Nephthea laevis ; Verseveldt 1974b: 2 (Red Sea, Gulf of Aqaba, El Hamira; listed only; = Litophyton arboreum ).

Material examined.

ZMB 6818, holotype, Kükth det., Rotes Meer, Djidda, Pola Exp.; RMNH Coel. 6821, Red Sea, Gulf of Suez, Et Tur, 6. July 1969, coll. L. Fishelson; ZMTAU NS 8306, Red Sea, Gulf of Suez, El-Bilaiyim lagoon, 24 August 1971, coll. D. Popper; ZMTAU Co 25971, Red Sea, Gulf of Suez, Jubal Is., Bluf point, depth 4 m, 24 March 1988, coll. Y. Benayahu; ZMTAU Co 26126 3211, Red Sea, Gulf of Suez, between Shaduan and Tawilla Is., 25 September 1989, coll. Y. Benayahu; ZMTAU Co 26231, Red Sea, Gulf of Suez, Ras Gahra, 26 September 1974, coll. Y. Benayahu; ZMTAU Co 28550 (E258); Red Sea, Dahlak Archipelago, Daliacus; depth 3 m; 18 October 1993, coll. Y. Benayahu; ZMTAU Co 28585 (E121), Red Sea, Dahlak Archipelago, Dur Gam, depth 3 m, 14 October 1993, coll. Y. Benayahu.

Removed from the species.

RMNH 8941, Red Sea, Gulf of Aqaba, Ophir Bay, 30 August 1967, coll. Hebrew Univ.- Smiths. Red Sea project (identified by Verseveldt as Nephthea laevis = Litophyton arboreum ).

Diagnosis.

Litophyton with the internal spindles of the base of the stalk short and slender, up to 0.15 mm wide and 0.5 mm long.

Description.

The holotype is 8 cm high and 5 cm wide; the short colony stalk divides in several main stems shortly above its base (Figure 36A). Polyps are crowded at the end of the lobes arranged in globular to oval-shaped structures.

The polyps are up to about 0.7 mm high and 0.6 mm wide (Figure 37A). Supporting bundle not projecting, composed of spindles with simple tubercles, outer side and distal end with larger tubercles. Length of these spindles is up to 0.8 mm (Figure 37B). Polyp body sclerites irregularly arranged, the smallest are present adaxially; abaxially they merge into the smaller spindles of the supporting bundle (Figure 37C). The tentacle sclerites resemble the smallest adaxial polyp sclerites (Figures 37D, 39 B–C).

Surface layer top of stalk. Rods and spindles, up to 0.45 mm long, with simple tubercles (Figure 37E).

Surface layer base of stalk. Radiates and derivatives of these, up to 0.15 mm long, with simple tubercles; a few are unilaterally spinose (Figure 38A). A few spindles and unilaterally spinose spindles are also present, up to 0.45 mm long, with simple tubercles.

Interior base of stalk. Spindles, up to 0.5 mm long, with simple sparse tubercles (Figure 38B). Several spindles have one or more side branches.

Colour. The colony is whitish.

Distribution.

Red Sea: Gulf of Suez, Dahlak Archipelago.

Remarks.

Kükenthal (1913) mentioned four specimens with his description, in Berlin I found only one specimen, labelled holotype, which is the same one that Kükenthal used in his description. He mentioned longer interior spindles, up to 1 mm long. I assume I missed the longer ones as only few interior spindles are present in the microscope slide made of the stalk of ZMB 6818.

The species can be confused with Litophyton simulatum , but the latter has wider, more branched internal spindles.

ZMTAU Co 26126 3211 has been used for SEM images of sclerites (Figures 39-41).

RMNH Coel. 8941 has spindles up to 1.3 mm long in the interior of the stalk, quite some of them with blunt ends and therefore I re-identified it as Litophyton arboreum .