Plumigorgia hydroides Nutting, 1910

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 : 368-369

Plumigorgia hydroides Nutting, 1910

Figures 25 , 26B, 26C , 27

MATERIAL EXAMINED.— CASIZG 180888; Philippines, Palawan Province, Calamian Group, Busuanga Island; 10 m depth; 24 February 2010; coll. G.C. Williams; one colony in several pieces wet-preserved in 95% ethanol. CASIZG 207506; Philippines, Palawan Province, Calamian Group, Busuanga Island; 12 m depth; 24 February 2010; coll. G.C. Williams; one partial colony wet-preserved in 95% ethanol.

REMARKS.— Colonies with branches that are planar and pinnate, very thin, gracile, and flexible. Sclerites are small plate-like structures, more-or-less ovoid in shape, with coarse surfaces and no tubercles. Some sclerites are slightly restricted in the middle. Retracted polyps form numerous, minute conical bumps on the branches, or they retract completely into the coenenchyme. Colony color in life is white or cream-white.

SPECIES.— There are five described species in the genus — Plumigorgia hydroides (Indonesia, Philippines, Northwestern Australia); P. schuboti Alderslade, 1986 (Great Barrier Reef, New Caledonia); P. terminosclera Alderslade, 1986 and P. astroplethes Alderslade, 1986 (Great Barrier Reef) and P. wellsi Bayer, 1955 (Marshall Islands).

OCCURRENCE AND DISTRIBUTION.— Plumigorgia hydroides is a presumably zooxanthellate species that inhabits shallow coral reef flat and gentle slopes that exhibit frequent periods of substantive water movement. In has been observed in the eastern part of the central Philippines in the vicinity of Busuanga Island.

REFERENCES.— Alderslade (1986b); Bayer (1955); Bryce and Poliseno (2014); Fabricius and Alderslade (2001); Grasshoff and Bargibant (2001).

Figures

FIGURE 25. Plumigorgia hydroides. A-B. Underwater photographs in situ, Busuanga Island – Calamian Group, Palawan Province, 9-12 m depth, February 2010.

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.

FIGURE 27. Plumigorgia hydroides, scanning electron micrographs.A. Surface of axis: Left, portion of axis near a distal branch tip, scale bar = 0.2 mm. Right, magnified detail of surface showing slit-like surface perforations, scale bar = 0.02 mm. B. Coenenchymal sclerites, scale bar = 0.02 mm