Sarcophyton minusculum, Namin, Samimi & Ofwegen, Van, 2009

Namin, Samimi & Ofwegen, Van, 2009, Some shallow water octocorals (Coelenterata: Anthozoa) of the Persian Gulf, Zootaxa 2058, pp. 1-52 : 4-8

publication ID	https://doi.org/ 10.5281/zenodo.186743
DOI	https://doi.org/10.5281/zenodo.6220135
persistent identifier	https://treatment.plazi.org/id/03A36F53-CA62-5A69-F0EC-FC6DFD3968AE
treatment provided by	Plazi
scientific name	Sarcophyton minusculum
status	sp. nov.

Treatment

Sarcophyton minusculum View in CoL n. sp.

( Figs. 2a–b View FIGURE 2. a – b , 3–4 View FIGURE 3 View FIGURE 4 )

Material: Holotype, RMNH Coel. 38756, Larak Island, 26º 53' 15.40" N, 56º 23' 36.86" E, depth 5–7 m, coll. K. Samimi Namin, 3 January 2007.

Paratype: RMNH Coel. 38757, same data as holotype.

Description. The holotype is 5 cm high, the stalk is rather short, only 2 cm high ( Fig. 2a–b View FIGURE 2. a – b ). The polyparium is 6 cm by 9 cm in diameter, its margin is strongly folded.

The polyps have eight points with many sclerites; flattened rods, up to 0.35 mm long, with a few simple tubercles. The tentacles also have many rods, similar to those of the points, but smaller in size, the largest being 0.10 mm long ( Fig. 3 View FIGURE 3 a).

The surface layer of the polyparium has many small capstans, about 0.05 mm long ( Fig. 3 View FIGURE 3 b), and clubs with poorly developed heads ( Fig. 3 View FIGURE 3 c); these clubs are 0.07–0.25 mm long.

The interior of the polyparium has slender spindles, with simple tubercles or spines ( Fig. 3 View FIGURE 3 d); these spindles are up to 0.45 mm long.

The surface layer of the stalk has capstans and clubs, similar to those of the polyparium. The capstans are somewhat longer than those in the polyparium ( Fig. 4 View FIGURE 4 a), the clubs somewhat shorter ( Fig. 4 View FIGURE 4 b).

The interior of the stalk has spindles with spines, or simple or complex tubercles ( Fig 4 View FIGURE 4 c–d). These spindles have the same length as those of the interior of the polyparium, but are distinctly wider.

Colour. Alive the holotype was bluish to greenish, with brown polyps. Preserved it is light brown.

Etymology. The Latin “minusculus”, rather small, refers to the small spindles in the interior of the stalk.

Variability. The paratype is of similar size as the holotype, but has a shorter stalk. Its sclerites resemble those of the holotype.

Remarks. According to the groupings of Verseveldt (1982: 10) the present species falls in his group III, “in surface disc are small sclerites along with larger ones, which are not club-shaped, but rods, spindles, ovals or irregularly formed bodies”. In this group almost all species have spindles in the interior which are twice as long as in S. minusculum . Only S. flexuosum Tixier-Durivault, 1966 , has similarly sized spindles, up to 0.50 mm long. But this species has no clubs at all in the surface layer of the polyparium while S. minusculum has many.

Because of the small sized interior spindles we also compared the species with those included by Verseveldt in his group I, “most coenenchymal sclerites are short, up to about 0.40 mm long”. In this group only S. spongiosum Thomson & Dean, 1931 , and S. tenuispiculatum Thomson & Dean, 1931 , have mushroom-shaped colonies with surface layer clubs with poorly developed heads. Both of these differ in lacking the capstans in the surface layer of the polyparium, having needles in the interior of the polyparium and ovals in the interior of the stalk.

It is noteworthy that we have noticed that the differences between S. spongiosum and S. tenuispiculatum are very small and probably only based on different sclerite sampling positions on the colony, as the lectotype of S. spongiosum is missing the base of the stalk.