Litophyton Forskal , 1775

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 : 3-4

Taxon classification Animalia Alcyonacea Nephtheidae

Litophyton Forskal, 1775

Litophyton Forskål, 1775: 139.

Ammothea Lamarck, 1816: 410.

Nephthee Savigny, 1817: pl. 2 fig. 5 (plates of the text of Andouin)

Nephthea Audouin, 1828: 49.

Nephthya Ehrenberg, 1834: 284.

Neptaea Blainville, 1834: 523.

Nephtya Van Beneden, 1867: 197.

Amicella Gray, 1869: 123.

Verrilliana Gray, 1869: 130.

Litophytum Kükenthal, 1903: 106.

Diagnosis.

Nephtheids with bushy and arborescent colonies. Polyps clustered at the end of the terminal branches, forming catkins. Polyps non-retractile, without or with supporting bundle, sometimes completely unarmed. Sclerites of surface layer of branches, stem and stalk are spindles and unilateral spinose spindles, the colony stalk also contains capstans and derivatives of capstans. Interior of the stalk has sparsely tuberculated spindles. Colonies zooxantellate.

Type species.

Litophyton arboreum Forskål, 1775, by monotypy.

Remarks.

Because of the synonymy of Nephthea with Litophyton , for many species a spelling emendation needed to be made to comply with ICZN Art. 31.2 in relation to gender agreement between generic and species names.

Characters used.

Litophyton species are known to have extreme intraspecific variation in colony shape and sclerites ( Verseveldt 1973). For the Red Sea and Indian Ocean the number of nominal species is 26, but in the present study this number has been reduced to 13 valid species, including a new one, whereas 13 species have been synonymized or assigned to other genera (see below).

Colony shape did not prove to provide a reliably constant character. A good example is Litophyton? savignyi , which may resemble some other Litophyton species but can also have a colony shape like that seen in some species of Stereonephthya (Figures 50-51).

The polyp armature showed some useful characters but some sclerite arrangements were observed in various species: Litophyton chabrolii (Figure 2B), Litophyton laevis (Figure 2A), Litophyton simulatum (Figure 2D), and Litophyton striatum (Figure 2C), Only one species, Litophyton? savignyi had a projecting supporting bundle; three had small rodlets in the polyp stalk, Litophyton arboreum , Litophyton curvum and Litophyton filamentosum ; two had rodlets in the polyp head, Litophyton maldivensis and Litophyton viridis ; one lacked sclerites in the adaxial polyp part, Litophyton bumastum and the remaining five species had spindles all over the polyp, Litophyton chabrolii , Litophyton laevis , Litophyton lanternarium , Litophyton simulatum , and Litophyton striatum .

The sclerites of Litophyton species show a staggering morphological variation, with those in the polyp and stem and stalk surfaces varying most in shape. Notably, the shape of the stalk surface sclerites is different depending on the height on the stalk. The least variable sclerites are the spindles of the internal canals. As with the polyp armature some species have the same types of spindles, which limits the usefulness of these sclerites.