Pacifigorgia smithsoniana, 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 : 10-12

Pacifigorgia smithsoniana , new species

( Figs. 1 E–F, 4A–E)

Material examined. Holotype: UCR 1406, Islote Frijol South, Gulf of Chiriquí, 2–5 m, H.M. Guzman, 24 April 2002.

Paratypes: MCZ 57052, Punta Jicarón Nor­West, Gulf of Chiriquí, 3–6 m, H.M. Guzman, 18 April 2002; STRI 486, Bajo Foul, Península de Azuero, 15 m, H.M. Guzman, 11 April 2003; STRI 565, Islas Viudas, Gulf of Chiriquí, 4–6 m, H.M. Guzman, 18 April 2002; STRI 672, 673, Isla Pacora, Gulf of Chiriquí, 2–10 m, H.M. Guzman, 7 May 2003; UCR 1216, Punta Jicarón Nor­West, 3–6 m, H.M. Guzman, 18 April 2002; UCR 1422, 1423, Isla Brincano, Punta South­West, 3–15 m, H.M. Guzman, 27 April 2002; UCR 1429, 1430, Bajo Urracá, 3–20 m, H.M. Guzman, 27 April 2002.

Description. Colonies wider than high, up to 150 in height, and 220 mm in width, composed of one or more fans. New fans arise from the others and grow parallel to them. Colour when wet preserved is reddish­orange and dark red when dry; when alive they range from red to dark red. Colonies of different coloured hues can be found on the same site, even on the same rock. Colonies have a strong holdfast, and the fans commonly arise directly from this, but some colonies have short stems up to 10 mm in length. Networks are regular and of closed meshes ( Fig. 1 F), mostly angular, up to 7 mm in length and 3 mm in width (about 8–9 meshes/cm²). Mesh branches are squarish in section, up to 2.0 mm in diameter. There are no distinct midribs, but some thick basal branches (up to 10 mm in width) can be traced for short distances into the fans. End­branchlets are more rounded than squarish in section, up to 5 mm in length, and have pointed tips. Free­twigs are short (up to 3 mm in length). The polyps are retracted within dome­shaped, coenenchymal mounds which are slightly raised, and closely crowded on the branches. They are mostly arranged in two to four alternating rows along the branches; more on thick branches. There is a very thin rim of orange sclerites around the polyp apertures. Polyps are white with rods arranged in weak points, some very small biscuit­like rods are found at the base of the tentacles. Coenenchymal sclerites are different combinations and abundances of pink, and hues of red, from reddish­orange to pale yellow, and also multicoloured; many of them show a yellowish halo. The surface of the branches contains dark yellow capstans sparsely distributed on a solid layer of orange and reddish­orange, larger capstans and spindles. In some specimens, however, almost all sclerites have the same colour, generally reddish­orange, but a shine from yellow sclerites on the branches can always be seen. The coenenchymal sclerites are mostly wide capstans and spindles, robustly tuberculate, becoming barrel­like. Anthocodial sclerites are light yellow rods.

Holotype. The holotype ( Fig. 1 E) is a dry, deep red colony, mostly a single fan, and 120 mm in height, and 200 mm in width. The holdfast was broken at the time of collection. No complete midribs are present, but a thick branch (up to 10 mm in width) at the base subdivides in two thinner ones, which extend up to 70 mm into the fan. At the base of the colony the black axis is visible. Some short branches spread at right angles to form three very small secondary fans at different levels of the colony. The coenenchymal sclerites are mostly wide capstans and spindles, strongly ornamented, mainly reddish­orange, but some are mixtures of these colours. The spindles (up to 0.14 mm in length and 0.05 mm in width) have a complex ornamentation, mostly arranged as four whorls of warty tubercles.

The ends are elongate, pointed or rounded, and abundant asymmetric forms occur with one blunt end and the other acute ( Fig. 4 A): a few spindles are arched. The capstans are mostly large (up to 0.10 mm in length and 0.05 mm in width), with strong, warty tubercles. The most characteristic capstans are light red with a clearly marked waist and two tyre–like whorls of tubercles ( Fig. 4 B), which are frequently found in sclerite samples. Less abundant smaller capstans, dark yellow (about 0.05 mm in length and 0.04 mm in width) with wide tubercles ( Fig. 4 B) are also present. Four­radiates (up to 0.06 by 0.06 mm) with warty ends ( Fig. 4 C), and various immature types of sclerites are present ( Fig. 4 D). Anthocodial sclerites are yellow, sometimes pale. They are long rods (up to 0.11 mm in length and up to 0.03 mm in width) mostly with smooth or wavy margins, and some with short lobe­like projections ( Fig. 4 E).

Habitat. This species occurs scattered in patches among other more abundant species, such as P. rubinoffi , P. rubicunda , and P. f i r m a.

Etymology. In honour of the Smithsonian Tropical Research Institute located in the Republic of Panama; for decades of support to basic research in tropical marine coastal ecosystems.

Distribution. Only reported for the type localities.

Figures

FIGURE 4. Pacifigorgia smithsoniana, new species (UCR 1406); SEM­micrographs of the sclerites: A – D, from the coenchyme; 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).