Calibelemnon indicum (Thompson and Henderson, 1906)

Williams, Gary C., 2018, Illustrated Key and Synopses of Shallow-water Gorgonians and Pennatulaceans of the Central Philippines, Part 2 (Cnidaria: Anthozoa: Octocorallia), Proceedings of the California Academy of Sciences 64 (13), pp. 361-398 : 369

Calibelemnon indicum (Thompson and Henderson, 1906)

Figure 26A

MATERIAL EXAMINED.— CASIZG 201545; Philippines, Luzon, Batangas Province, Calumpan Peninsula, Balayan Bay (13.72 N 120.87 E); 40 m depth; 2 May 2014; coll. Peri Paleracio; one whole colony wet-preserved in 95% ethanol.

REMARKS.— Calibelemnon indicum is a very thin and delicate sea pen with two longitudinal columns of polyps, in which the polyps are oppositely arranged along the length of the rachis. The axis is visible through the thin tissues of the rachis and peduncle. Siphonozooids are conspicuous as numerous low mounds in opposite columns along the rachis. Sclerites are absent altogether.

SPECIES.— Four species are described — Calibelemnon hertwigi (Balss, 1909) , Calibelemnon symmetricum Nutting, 1908 , Calibelemnon indicum (Thomson and Henderson, 1906) , and Calibelemnon francei Williams and Alderslade, 2011 . The latter two species are considered valid, while the status of the former two is uncertain.

OCCURRENCE AND DISTRIBUTION.— Calibelemnon is a rarely encountered genus from mesophotic depths and the deep-sea in the Indo-West Pacific (southeastern Africa to Japan and the Philippines, 40-1275 m) and the Western Atlantic (Bahamas Escarpment, 1969 m). In the Philippines, Calibelemnon indicum is known only from a single collection off the Calumpan Peninsula at 40 m depth, inhabiting deeper reefs in areas of unconsolidated sediments.

REFERENCES.— Kükenthal (1915); Ofwegen (2010c); Williams (1990); Williams (1995); Williams (1999); Williams (2011); Williams and Alderslade (2011).

Figures

FIGURE 26. A. Calibelemnon sp., wet-preserved whole specimen (CASIZG 201545), scale bar = 15 mm. B. Plumigorgia hydroides, wet-preserved specimens (CASIZG 207506), scale bar = 20 mm. C. Plumigorgia hydroides (CASIZG 180888), scale bar = 35 mm.