Eugorgia purpurascens Verrill, 1868

Breedy, Odalisca, Guzman, Hector M. & Vargas, Sergio, 2009, A revision of the genus Eugorgia Verrill, 1868 (Coelenterata: Octocorallia: Gorgoniidae), Zootaxa 2151, pp. 1-46 : 27

Eugorgia purpurascens Verrill, 1868

Figure 13 , Plate 9A–C

Eugorgia ampla var purpurascens Verrill, 1868: 408 ; Bielschowsky 1929: 175. Eugorgia ampla purpurascens Kükenthal 1924: 345 .

Material examined. Syntypes: YPM 1630, dry, Pearl Islands, Panama, no depth given, F.H. Bradley, 1866- 67; YPM 1613, dry, Zorritos, Peru, no depth given, F.H. Bradley, 1866-67; YPM 4623, Corinto, Nicaragua, no depth given, J.A. McNiel, no date.

Description. Colonies measure up to 48 cm in height, and up to 37 cm in width; they are deprived of a holdfast. Branching is irregularly dichotomous. Branches compressed at their base, reaching 13–25 mm in diameter; unbranched terminal twigs are 3–8 mm in diameter, more cylindrical, and slightly tapered at the ends, with rounded tips about 1–2 mm in diameter. Branches and branchlets can be sinuous; some branchlets divide at obtuse angles. Unbranched final twigs reach up to 10 cm in length. Colonies are light purple to pinkish (Plate 9A). Slightly marked longitudinal grooves occur along the branches, and near the base and the polyps were evenly distributed all around (Plate 9B). Polyp mounds are slightly raised and placed close together on the branch surface (Plate 9A–B). Polyp-apertures are small, up to 0.5 mm in diameter. Coenenchymal sclerites are colourless, pink, and some bicoloured, or they are mostly colourless with some pinkish (Plate 9C). In specimen YPM 1613, sclerites are colourless, pink and purple, and mostly double discs. In specimen YPM 1630 sclerites are colourless and pale pinkish with an even occurrence of double discs and spindles in the slide-samples. Shapes and sizes of sclerites are consistent among the type series. Double discs reach up to 0.07 mm in length and 0.05 mm in width (Plate 9C, Fig. 13 ); capstans are about the same size. Spindles are up to 0.13 mm in length, and 0.05 mm in width, with 4–6 whorls of warty tubercles (Plate 9C, Fig. 13 ). Furthermore, some crosses are present, up to 0.08 by 0.07 mm ( Fig. 13 ). No anthocodial sclerites were found in the samples for study.

The illustrated specimen (YPM 1630) is a large portion of a fan, 45cm in height, 37 cm in width, and 2.5 cm in diameter at the base (Plate 9A).

Distribution. Pearl Islands, Corinto, Zorritos, type localities (Verrill 1868) ( Table 4).

Remarks. Verrill described this species as a variety of E. ampla but they differ in many aspects: colonies are not bushy as in E. ampla , they are more flexible, and the colour of the colonies and sclerites in this species is never orange, as is the case in E. ampla ; spindles are smaller than in E. ampla , and also less abundant; no complete double discs were found in E. purpurascens (Tables 1–2). These species differ not only in the morphology but also in geographic distribution; E. purpurascens has not been reported for any site in Baja California, type locality of E. ampla . Therefore, we consider E. purpurascens as a separate species ( Table 4).

Figures

FIGURE 13. Eugorgia purpurascens (YPM 1630), coenenchymal sclerites.