Sarcophyton subviride Tixier-Durivault 1958
Creators: name: Benayahu, Yehuda
name: Van Ofwegen, Leen P.
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Cnidaria
Anthozoa
Alcyonacea
Alcyoniidae
Sarcophyton
Sarcophyton subviride

description: Sarcophyton subviride Tixier-Durivault, 1958
(Figs 2-4; 14E, F)
MATERIAL EXAMINED. — ZMTAU Co 34408 and 4 microscope slides, Co 34411 (2 colonies), Saint-Paul, l’Ermitage face au ponton au kiosque (21°04’10.33”S, 55°12’58.46”E), reef slope, 14-19 m, 7.IV.2008. — RMNH Coel 40121, ZMTAU Co 34461 (2 colonies), Saint-Leu, Pointe des Châteaux (21°09’04.39”S, 55°16’12.47”E), reef slope, 14-20 m, 10.IV.2008.
DISTRIBUTION. — Previously known from Aldabra Island, North of Madagascar (type locality). Reunion (new record).
DESCRIPTION
Co 34408 is an encrusting colony, exhibiting a rather soft texture. Polyparium with a maximum cross-section of 8.5 × 4.5 cm and a height of up to 4 cm (Fig. 2). Polyparium folded, directed towards colony base. All polyps retracted.
Tentacles with scale- and rod-sclerites, up to 0.14 mm long (Fig. 3A). Point sclerites with slight indentation at their ends, up to 0.19 mm long (Fig. 3B).
Surface of polyparium with clubs, smallest 0.09 mm long and longest up to 0.30 mm (Fig. 3C). Clubs featuring ill-defined head and tubercular prominences, also along handles. Interior polyparium with slender tubercular spindles, some slightly curved, up to 0.58 mm long (Fig. 3D).
Surface of base with tubercular clubs, 0.11- 0.16 mm long (Fig. 4A) and spindles 0.10-0.17 mm long featuring zoned tubercles (Fig. 4B). Interior of base containing tubercular spindles, including stout and oval ones, up to 0.41 mm long (Fig. 4C).
Colour
In alcohol, preserved specimen beige with light brown stalk.
Living features
Colonies with beige-yellowish polyps; folded margins evident (Fig. 14E, F).
VARIABILITY
The paratypes differ in size: RMNH Coel 40121 with a maximum cross-section of 6 × 6 cm and a height of up to 3 cm; ZMTAU Co 34461: 2 colonies, 4.5 × 2.5 × 2.5 cm and 3 × 2.5 × 2 cm respectively; ZMTAU Co 34411: 2 colonies, 5 × 4 × 2 cm and 5.5 × 4.5 × 2.4 cm respectively.
REMARKS
Verseveldt (1982) redescribed the type of S. subviride. The colony shape of the type therein (pl. 22, fig. 2) resembles the currently examined colonies, although many of the polyps are not retracted.The redescription referred to flat tentacle rods and additional rods, arranged en chevron, corresponding to the polyp points (p. 78), but neither type of sclerites was depicted by Verseveldt (1982). We examined polyp mounts of the types deposited at RMNH and confirmed that the polyp sclerites there correspond to those depicted in the current description (Fig.3A, B). Unfortunately, most taxonomists examining Sarcophyton species have overlooked the polyp sclerites and therefore excluded them from the original descriptions. This also applies to Verseveldt’s 1982 revision of the genus, with the exception of S. pulchellum (Tixier-Durivault, 1957) (fig. 26 therein). Later descriptions of new Sarcophyton species indicated an absence of polyp sclerites (e.g., S. nanwanensis Benayahu & Perkol-Finkel, 2004 and S. tumulosum Benayahu & Van Ofwegen, 2009). These sclerites might be an important taxonomic feature, as has been proven for the speciose genus Sinularia (e.g., Van Ofwegen 2008).
The sclerites of the examined material are in general agreement with the description of the type of S. subviride (see Verseveldt 1982: 78, 79). However, in the surface of the base we found clubs, up to 0.16 mm long (Fig. 4A); whereas, according to Verseveldt, in the type they are up to 0.30 mm long. Similarly, the spindles of the base (Fig. 4C) are shorter compared to the type (up to 0.41 vs 0.6 mm, respectively). We consider these differences as reflecting intra-specific variation within S. subviride. Notably, our material constitutes the second finding of S. subviride since the collection of the type in Aldabra Island (north of Madagascar); and with its current finding in Reunion, it seems to have a bi-equatorial Indian Ocean distribution.
description: Published as part of Benayahu, Yehuda & Van Ofwegen, Leen P., 2012, Octocorals (Cnidaria, Anthozoa) from Reunion, with a description of two new species of the genus Sinularia May, 1898 and notes on the occurrence of other species, pp. 673-699 in Zoosystema 34 (4) on pages 676-677, DOI: 10.5252/z2012n4a2, http://zenodo.org/record/5166480