Heterogorgia tortuosa Verrill, 1868

Breedy, Odalisca & Guzman, Hector M., 2011, A revision of the genus Heterogorgia Verrill, 1868 (Anthozoa: Octocorallia: Plexauridae), Zootaxa 2995, pp. 27-44 : 33-37

Heterogorgia tortuosa Verrill, 1868

( Figs. 6 , 7 )

Heterogorgia tortuosa Verrill, 1868: 414 ; Verrill 1869: 452 –454; Kükenthal 1924: 231; Harden 1979: 113 –114. Heterogorgia verrucosa Castro 1990: 412 –415.

Material examined. Lectotype (here designated): YPM 1555d dry, Pearl Islands, Panama, depth not given, F. H. Bradley, 1866–1867.

Paralectotypes: BM 1950.31.62.45, YPM 1555a–c, MCZ 4910 dry, Pearl Islands, Panama, depth not given, F. H. Bradley, 1866–1867.

Other material. COSTA RICA: UCR 501, dry, Ana Bay, Caño Island, 17 m, H. Guzman, 10 February 1984; UCR 1854, preserved in ethanol, Nicoya Gulf, 11 m November 2002, O. Breedy; UCR 1865 (3), preserved in ethanol, Matapalo, Port Jiménez, 25 m, O. Breedy, 13 March 2004; UCR 1864 (2), preserved in ethanol, Ballena Marine National Park, 19 m, O. Breedy, 24 April 2002. PANAMA: UCR 1863 (2), preserved in ethanol, Jicarita southwest, Coiba Island, 21 m H. Guzman, April 2002; UCR 1858 (3), preserved in ethanol, Frailes south, 15 m, H. Guzman, December 2001; UCR 1862, preserved in ethanol, Bajo Viuda, Coiba Island, 18–20 m, H. Guzman, 22 April 2002; STRI 305, dry, Bajo La Viuda, 30 m, H. Guzman, 23 April 2002; SRTI 236, 237, dry, Islote, 10 m, H. Guzman, 20 April 2002; STRI 368, dry, Otoque Island, 5–10 m, H. Guzman, 9 May 2002.

Description of the lectotype. The colony is 13.5 cm tall and 8 cm wide ( Fig. 6 A–B) with a short stem that branches irregularly up to seven times. The branch diameter is 3–4 mm, and some are lacking coenenchyme, exposing the dark axis. Only a very small portion of the holdfast is preserved. The polyps retract into prominent calyces up to 1 mm tall and up to 1.5 mm diameter ( Fig. 6 B), and are sparsely distributed around the branches, about 1.5 mm apart, and even more distant at the base of the branches and on the holdfasts, up to 4 mm apart ( Fig. 6 A). Anthocodial armature consists of collaret and points. The collaret is composed of two whorls of long curved spindles, 0.27–0.55 mm long and 0.03–0.08 mm wide, which are covered with small spines ( Fig. 7 A); the points are composed of 2–3 pairs of spiny spindles arranged en chevron; they are 0.16–0.34 mm in long and 0.02–0.05 mm wide ( Fig. 7 B). The tentacles bear thorny rods, and crescents 0.09–0.2 mm long and 0.03–0.04 mm wide, that are ornamented on their convex side with tubercles and thorn-like processes ( Fig. 6 C). The calicular rim has two whorls of thick warty thorns that are 0.18–0.30 mm long and 0.04–0.05 mm wide ( Fig. 7 C). Coenenchymal sclerites comprise: small tuberculate radiates, 0.07–0.12 mm long and 0.06–0.09 mm wide ( Fig. 7 F); crosses, 0.09–0.2 diameter ( Fig. 7 E), with tuberculate arms; and spindles 0.12–0.4 mm long and 0.045–0.13 mm wide ( Fig. 7 D), that can be branched, straight or bent, and have the tips acute or irregularly tuberculate.

Colour of the colony is whitish.

Variability. The other specimens examined reach up to 14 cm tall, and 10 cm wide. The stems are connected by a continuous encrusting holdfast and subdivide close to the base into several slightly flattened branches, up to 6 mm diameter, that re-branch often in an irregular manner. When alive, the polyps are bright yellow, and the coenenchyme looks reddish or brownish ( Fig. 1 C). Some variation in the size of sclerites has been found in some specimens. All other characteristics are as described for the lectotype.

The colour of the colonies is whitish to beige or brownish in ethanol or dry preserved.

Remarks. The type series of H. tortuosa consists mostly of colonies in bad condition and specimen YPM 1555d was selected as the lectotype to establish the species’ identity because of its better state of preservation.

This species is reported only for Costa Rica and Panama.

A comparison of this species with others is included in the Remarks section for H. verrucosa .

Figures

FIGURE 1. Submarine photographs: (A – B) H. hickmani, Galápagos Islands, Ecuador (Photographs by H. P. Hickman); (C) H. tortuosa, Coiba Island, Panama; (D) H. verrucosa, Coiba Island.

FIGURE 6. Heterogorgia tortuosa, lectotype, YPM 1555 d: (A) colony; (B) detail of a branch; (C) tentacular sclerites.

FIGURE 7. Heterogorgia tortuosa, lectotype, YPM 1555 d, sclerites: (A) collaret spindles; (B) point spindles; (C) thorns; (D) spindles; (E) crosses; (F) radiates.