Litophyton, Forskal, 1775

Van Ofwegen, Leen P., 2020, The genus Litophyton Forskål, 1775 (Octocorallia: Alcyonacea: Nephtheidae) from Australia, Zootaxa 4764 (1), pp. 1-131 : 70-71

Key to the species of Litophyton group IV (3 species)

(polyp stalk without small rods)

1. Polyps with strongly developed sclerites................................................................ L. grandis

-. Polyps with less strongly developed sclerites.................................................................... 2

2. Big wide interior spindles (> 1 mm long) with very regular tubercles........................................ L. carnatum

-. Small slender interior spindles (<1 mm long); opaque polyp sclerites................................................ 3

3. Spindles with blunt ends present in interior of the base of the stalk.......................................... L. oxleyensis

-. No spindles with blunt ends...................................................................... L. pandoraensis

Remarks. As the polyps of L. oxleyensis mostly have scales it also fits group III, where it was described.

L. compactum ( Verseveldt, 1966) , described from Indonesia, falls in this group ( Figs. 42 g-h, 56b, 57). It has similar tuberculated interior stalk sclerites as L. carnatum but they are only about 1 mm long in L. compactum . It differs from L. pandoraensis by having the tuberculation of the interior stalk sclerites much finer, and from L. grandis , which has much stronger developed point sclerites.

L. elongatum ( Kükenthal, 1895) ( Ternate, Indonesia) resembles L. compactum but because of a large amount of detritus attached to the colony the polyp sclerite arrangement could not be drawn. However, the colony and sclerites are presented ( Fig. 56c , 58 ). The most obvious difference is the presence of long rods ( Fig. 58d ), which are not from the polyp stalk but are polyp spindles.

L. pyramidalis ( Kükenthal, 1895) ( Ternate, Indonesia) ( Figs. 56d , 59 ) shows sclerites similar to those of L. elongatum and therefore I here synonymize it with L. elongatum ( Kükenthal, 1895) . Especially the smooth spindles from the interior of the top of the stalk are strikingly similar in both species ( Figs. 58g , 59h ). The polyp sclerite arrangement of L. pyramidalis could be drawn ( Fig. 59a ).

Figures

FIGURE 42. Lateral views polyp armature of Litophyton species: a, L. brewerensis n. sp., holotype NTM C4050; b, L. legiopolypum (Verseveldt & Alderslade, 1982) holotype AMG 14806; c, L. oxleyensis n. sp., holotype NTM C4669; d, L. simplex n. sp., holotype NTM C3949; e, L. snakeensis n. sp., holotype NTM C10439; f, L. squamatum n. sp., holotype NTM C 4136; g-h, L. compactum (Verseveldt, 1966) holotype RMNH 2236 (after Verseveldt; magnification was not indicated by him).

FIGURE 56. Litophyton type specimens: a, L. nigrescens (Roxas, 1933), holotype SMF 61; b, L. compactum (Verseveldt, 1966), holotype RMNH 2236; c, L. elongatum (Kükenthal, 1895), holotype SMF 62; d, L. pyramidalis (Kükenthal, 1895), holotype SMF 63; e, L. carnatum n. sp., holotype NTM C4100. Scales 1 cm, a, e natural size.

FIGURE 58. Litophyton elongatum (Kükenthal, 1895), holotype SMF 62; a, abaxial point spindles; b, lateral point spindle; c, tentacle sclerites; d, polyp rods; e, supporting bundle spindle, partly; f, sclerites of surface layer top of stalk; g, spindles interior top of stalk; h, sclerites of surface layer base of stalk; i-j, spindles of interior base of stalk. Scale at c also applies to b, d; scale at h also applies to a, e, f, g, j.

FIGURE 59. Litophyton pyramidalis (Kükenthal, 1895), holotype SMF 63; a, lateral view polyp armature; b, abaxial point spindles; c, lateral point spindles; d, tentacle sclerites; e, the transversely arranged adaxial sclerites in 59a; f, supporting bundle spindle, partly; g, sclerites of surface layer top of stalk; h, spindles interior top of stalk; i, sclerites of surface layer base of stalk; j-k, spindles of interior base of stalk. Scale at c also applies to d, e; scale at i also applies to b, f, g, h, k.