Pacifigorgia ferruginea, Breedy, Odalisca & Guzman, Hector M., 2004

Breedy, Odalisca & Guzman, Hector M., 2004, New species of the gorgoniian genus Pacifigorgia (Coelenterata: Octocorallia: Gorgoniidae) from Pacific Panama, Zootaxa 541, pp. 1-15 : 4-5

Pacifigorgia ferruginea , new species

( Figs. 1 C–D, 3A–E)

Material examined. Holotype: STRI 423, Islas Ladrones, Gulf of Chiriquí, 15 m, H. Guzman and O. Breedy, 27 August 2002.

Paratypes: MCZ 57051, STRI 422B, UCR 1503 same data as holotype; STRI 521, Islas Ladrones, 5 m, H.M. Guzman, 15 April 2003; STRI 764, 765, Isla Galera, Gulf of Panama, 5 m, H.M. Guzman, 7 August 2003; UCR 1046, 1050, 1504, Isla Canal Afuera, Gulf of Chiriquí, 3–12 m, H.M. Guzman, 10 December 2001.

Description. Colonies wider than high, up to 110 in height, and 150 mm in width, composed of one or more fans. New fans radiate from different parts of the main fan and grow parallel. Colour when preserved is dark purple intermingled with orange, when alive it is a characteristic rust­colour, acquiring a lighter hue when dry. Orange sclerites, sparsely distributed on the surface of the branches, give the impression of rust on the colony, which is very distinctive for this species. Colonies have a strong holdfast, and the fans grow directly from this. Networks are regular and of closed meshes (6–7 meshes/cm²) ( Fig. 1 C), and about 2–5 mm in diameter. Some meshes are notably elongated and thin, about 15 mm in length and 1–1.5 mm in width. Small colonies have larger meshes. Mesh branches are squarish in section, up to 1.0 mm in diameter. No distinct midribs were observed, but some thick branches (up to 5 mm in width) at the colony base extend for a short distance (up to 15–20 mm) into the fans. End­branchlets are pointed, up to 7 mm in length. Free­twigs are around 3 mm in length, but in some colonies they reach up to 7 mm. The polyps are retracted within dome­shaped coenenchymal mounds which are slightly raised, and close together, with dark purple sclerites forming a thin ring around the polyp apertures. They are crowded on the branches and mostly arranged in pairs; although four rows occur on thick branches. Polyps are white with rods arranged in thin points, and with sparse intermediate (mesenterially arranged) rods. The rods are mostly colourless, pale pink or pale yellow; darker hues also occur. In some specimens (paratype, UCR 1050) the rods are light purple, especially in the centre with a lighter halo. Coenenchymal sclerites are large, wide capstans and spindles, with whorls of tubercles, and can be dark purple, orange to dark orange, and bicoloured with one end dark orange and the other dark purple. A combination of small orange capstans and large, wide, dark purple capstans and spindles is always observed in microscopic preparations. The majority

Holotype. The holotype ( Fig. 1 C) is a dry colony, 120 mm in height, and 140 mm in width, composed of a main fan, two small secondary fans, and some free branches at the base. The encrusting holdfast is attached to a small calcareous rock. No midribs cross the fans, but some thick, flat branches (up to 8 mm in diameter) extend from the holdfast for some distance, and the small secondary fans radiate perpendicularly from them, producing a star­like arrangement. Coenenchymal sclerites are dark purple, dark orange, orange, and some multicoloured. Spindles (up to 0.15 mm in length and 0.06 mm in width) have 4–6 complete whorls of tubercles, elongated warty ends ( Fig. 3 A), and are acute at both tips, or asymmetrical, with one blunt end. Capstans may be very large (up to 0.10 mm in length and 0.06 mm in width), with strong, warty tubercles, or small, and always orange (about 0.04 mm in length and 0.03 mm in width) ( Fig. 3 B). Some four­radiates (up to 0.09 mm in length by 0.09 mm in width) with warty ends ( Fig. 3 C) and various immature sclerites ( Fig. 3 D) are commonly found in the samples. Anthocodial sclerites are light yellow to colourless. They are flat, wide rods (up to 0.09 mm in length and up to 0.03 mm in width) with lobed or scalloped margins ( Fig. 3 E).

Remarks. Although some similarity exists in the size and shape of sclerites of P. f e r ­ ruginea and P. smithsoniana new species, the latter is more variegate in colour and has more barrel­like sclerites. A marked difference is also found in the anthocodial rods, which are longer in P. smithsoniana and are without wide lobed margins. When alive, the species are very different, notably the remarkable rusted aspect of the colonies of P. ferruginea .

Habitat. This species was abundant at Isla Ladrones growing on vertical walls from 14 to 15 m in depth, together with a species of Leptogorgia .

Etymology. An adjective (L), ferrugineus = rust­coloured, rusty.

Distribution. Only reported for the type localities.

Figures

FIGURE 3. Pacifigorgia ferruginea, new species (STRI 423); SEM­micrographs of the sclerites: A – D, from the coenenchyme; E, from the anthocodia.

FIGURE 1. A – B, Pacifigorgia catedralensis, new species (UCR 1514) (preserved specimen); C – D, Pacifigorgia ferruginea, new species (STRI 423) (dry specimen); E – F, Pacifigorgia smithsoniana, new species (UCR 1406) (dry specimen); G – H, Pacifigorgia sculpta, new species (UCR 1497) (preserved specimen).