Litophyton acuticonicum (Verseveldt, 1974)

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 : 6

Taxon classification Animalia Alcyonacea Nephtheidae

Litophyton acuticonicum (Verseveldt, 1974) Figures 1H, 3, 4, 5, 6, 7, 8, 9, 10, 11

Nephthea acuticonica Verseveldt, 1974b: 28, figs 20-21, pl. 9 (El Kura’, Gulf of Aqaba, Red Sea); McFadden et al. 2011: 25.

Litophyton acutifolium ; Verseveldt 1974b: 25, figs 19-18 (Gulf of Aqaba, Red Sea).

Litophyton acuticonicum Not Litophyton acutifolium Kükenthal, 1913: 12 (= Litophyton viridis ).

Nephthea striata ; Verseveldt 1974b: 2 (listed).

Material examined.

RMNH Coel. 8920, part of holotype, Red Sea, Gulf of Aqaba, El Kura, trawling, 14 September 1967, Hebrew Univ.-Smiths. Red Sea project, 118/SLR 533; RMNH Coel. 12318, Red Sea, Gulf of Aqaba, Ras Muhammad, depth 12 m, 6 September 1976, coll. Y. Benayahu; ZMTAU Co 25862 2051, Red Sea, Gulf of Suez, Shag Rock, depth 3-24 m, 14 July 1987, coll. Y. Benayahu; ZMTAU Co 25867 1354, Red Sea, South tip Sinai, Tiran St., depth 3-4 m, 25 June 1985, coll. Y. Benayahu; ZMTAU Co 25969 2170, Red Sea, South tip Sinai, Shab Mahmud, Beacon Rock, depth 27 m, 22 March 1988, coll. Y. Benayahu; ZMTAU Co 26190, Red Sea, South tip Sinai, Sharm el Maya, depth 6-12 m, 16 March 1981, coll. Y. Benayahu; ZMTAU Co 26191, Red Sea, Straits of Tiran, Ras Nazrani, 24 March 1981, coll. Y. Benayahu; ZMTAU Co 26202, Red Sea, Gulf of Aqaba Naqeb Shahin, depth 18 m, 15 June 1981, coll. Y. Benayahu; ZMTAU Co 26206, Red Sea, South tip Sinai, south of Naama, Amphores, depth 16-20 m, 7 June 1981, coll. Y. Benayahu; ZMTAU Co 26215, Red Sea, Gulf of Aqaba, Naqeb Shahin, depth 25 m, 29 June 1981, coll. Y. Benayahu; ZMTAU Co 26220, Red Sea, South tip Sinai, Naama Garden, depth 30 m, 30 June 1981, coll. Y. Benayahu; ZMTAU Co 26239, Red Sea.

Reassigned to the species.

RMNH Coel. 8483, identified by Verseveldt as Litophyton acutifolium , Red Sea, Elat, coll. M. Grasshoff; RMNH Coel. 8916, identified by Verseveldt as Litophyton acutifolium , Red Sea, Hebrew Univ.-Smith. Red Sea project, 49b/SLR L 388; RMNH Coel. 8939, identified by Verseveldt as Nephthea striata , Red Sea, Gulf of Aqaba, Fara 'un Island, 27 June 1967, Hebrew Univ.-Smiths. Red Sea project, 2/SLR 45; RMNH Coel. 8955, identified by Verseveldt as Litophyton acutifolium , Red Sea, Gulf of Aqaba, Marsa el Muqeilba, 6 January 1968, Hebrew Univ.-Smith. Red Sea project 64/SLR 1156.

Diagnosis.

Litophyton with branched spindles in the surface layer of the base of the stalk and large internal spindles in the base of the stalk, up to 2.0 mm long, the largest not branched.

Distribution.

Red Sea: Gulf of Suez, Gulf of Aqaba.

Remarks.

The species is sufficiently described by Verseveldt (1974b: 28). Here I give drawings of a polyp (Figure 3A), polyp sclerites (Figure 3B), base stalk internal (Figures 3C, 4B) and base stalk surface sclerites (Figure 4A) of the type. For showing variation, SEM images of sclerites of ZMTAU Co 25867 (Figures 5-8) and ZMTAU Co 26239 (Figures 9-11) are also presented.

RMNH Coel. 8483, identified by Verseveldt as Litophyton acutifolium , shows the polyp armature and large interior spindles that are characteristic of this species.

RMNH Coel. 8916 and RMNH Coel. 8955, also both identified by Verseveldt as Litophyton acutifolium , show the large internal stalk sclerites of this species. However, the polyps show an armature more like Litophyton viridis ( Litophyton acutifolium is synonymised with that species). This weak Litophyton viridis armature could represent intraspecific variation.

The species is characterized by the presence of branched spindles of the surface layer of the base of the stalk and the presence of large internal spindles in the base of the stalk, sometimes with blunt ends or branched. Litophyton arboreum also has internal spindles with blunt ends, but here the surface spindles of the base of the stalk are never branched. Litophyton simulatum can also have spindles with blunt ends but these are always less than 0.5 mm long, while in Litophyton acuticonicum they are up to 1.5 mm long. Sometimes also spindles with side branches are present in the interior of the base of the stalk (ZMTAU 26239, Figure 11c), similar to those of Litophyton striatum but that species never shows internal spindles of 2.0 mm long. It is noteworthy that these longer spindles with blunt end were not photographed with the SEM but were present in the microscope slides.