Heterogorgia hickmani Breedy & Guzman, 2005

Breedy, Odalisca & Guzman, Hector M., 2011, A revision of the genus Heterogorgia Verrill, 1868 (Anthozoa: Octocorallia: Plexauridae), Zootaxa 2995, pp. 27-44 : 30-32

Heterogorgia hickmani Breedy & Guzman, 2005

( Figs. 1 A–B, 2, 3)

Heterogorgia hickmani Breedy & Guzman, 2005: 803 –806; Castro et al. 2010: 779.

Material examined. Holotype: CDRS 03–95, ethanol preserved, La Botella, Floreana Island, Galápagos Islands, 7.5 m, C. Hickman, 19 January 2003.

Paratypes: CDRS 03–699, ethanol preserved, Pinzón Island, Galápagos Islands, 7.5 m, C. Hickman, 18 November 2003; CDRS Ang 156, four fragments, ethanol preserved, La Botella, 6 m, A. Chiriboga, 25 May 2004; CDRS Ang 139, fragment, ethanol preserved, La Botella, 11 m, A. Chiriboga, 8 February 2004.

Other material. ECUADOR: IIN 50, 78, dry, Gigima, Reserva de Producción Faunística Marino Costera Puntilla de Santa Elena, 12–14 m, F. Rivera, P. Martínez, R. Nebot and O. Breedy, 22 July 2010; IIN 122, dry, Los Ahorcados Islet, Provincia de Manabí, F. Rivera, P. Martínez, R. Nebot and O. Breedy, 10–12 m, 25 July 2010; GALÁPAGOS ISLANDS: CDRS Ang. 122, ethanol preserved, Gordons Rock, 24 m, A. Chiriboga, 23 January 2004; CDRS 04-167, ethanol preserved, Los Cañones, Isabela, 11 m, A. Chiriboga, 9 October 2004; CDRS 04-317, ethanol preserved, Caleta Negra, 15 m, A. Chiriboga, 30 November 2004; CDRS CDRS 04-326, ethanol preserved, Las Marielas, 3 m, A. Chiriboga, 2 December 2004; CDRS 04-359, ethanol preserved, La Botella, 15 m, A. Chiriboga, 4 December 2004; CDRS 04-367, ethanol preserved, Kicker Rock, San Cristóbal, 15 m,A. Chiriboga, 5 December 2004; CDRS 04-370, ethanol preserved, Five fingers, San Cristóbal, 15 m, A. Chiriboga, 5 December 2004; CDRS 04-380, ethanol preserved, Santa Fe, 24 m, A. Chiriboga, 6 December 2004; CDRS 07-101-102, ethanol preserved, Don Ferdi, Brainbridge Rocks, 24–26 m, O. Breedy, 9 March 2007; CDRS 07-114, ethanol preserved, Gordons Rock, 24 m, O. Breedy, 10 March 2007; CDRS 07-124, ethanol preserved, San Cristóbal, 15 m, C.P. Hickman, 11 March 2007; CDRS 07-193, ethanol preserved, Pinzón, 15 m O. Breedy, 2 March 2007.

Description. Colonies are composed of a few thick stems, branched or unbranched and slightly crooked with a rounded tip ( Figs. 1 A, 2A), that are up to 18 cm long, and are connected at their base by a continuous encrusting holdfast. The diameter of branches including calyces is up to 15 mm, and about 19 mm at tips. When alive, the polyps are bright yellow and the coenenchyme looks brownish ( Fig. 1 A–B). The polyps are densely packed around the branches (40–50 calyces/cm), more scarcely distributed on the holdfast and at the base of branches. The calyces are prominent, up to 2 mm diameter with a spiny lobed rim, and up to 1 mm tall ( Fig. 2 A–B). The anthocodial armature consists of a strong collaret and points arrangement. The collaret is composed of three rows of long curved spindles 0.5–0.7 mm long and 0.05–0.13 mm wide, with small warts on their surface; some have one or two short branchlike projections at one side ( Fig. 3 A). The points consist of five pairs of warty spindles and rods, 0.35–0.50 mm long and 0.04–0.06 mm wide, arranged en chevron ( Fig. 3 B). The calicular rim has 3–4 whorls of long, strong, thorns, 0.3–0.5 mm long ( Fig. 3 C). The coenenchymal sclerites include spindles, straight, bent or irregularly branched, 0.25–0.45 mm long and 0.10–0.15 mm wide ( Fig. 3 D); irregular warty ovals, 0.06– 0.12 mm long and 0.04–0.07 mm wide ( Fig. 3 F); and crosses that are up to 0.10–0.25 mm ( Fig. 3 E). The tentacular thorny rods are 0.08–0.20 mm long and 0.02–0.05 mm wide ( Fig. 3 G). A more detailed description is given in Breedy & Guzman (2005).

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

Remarks. The stems with just one or two wide branches, the large calyces arranged very close together, and the predominance of larger sclerites distinguish this species from all others. This species has been found at several sites in the Galápagos Islands and recently off the mainland coast of Ecuador. There are no records elsewhere in the eastern Pacific.

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 2. Heterogorgia hickmani, paratype, CDRS Ang. 156: (A) colony; (B) detail of a branch.

FIGURE 3. Heterogorgia hickmani, paratype, CDRS Ang. 156, sclerites: (A) collaret spindles; (B) point spindles; (C) thorns; (D) spindles; (E) cross; (F) irregular warty ovals; (G) tentacular rods.