Eugorgia aurantiaca ( Horn, 1860 )

Breedy, Odalisca, Guzman, Hector M. & Vargas, Sergio, 2009, A revision of the genus Eugorgia Verrill, 1868 (Coelenterata: Octocorallia: Gorgoniidae), Zootaxa 2151, pp. 1-46 : 15-16

Eugorgia aurantiaca ( Horn, 1860)

Figure 6 , Plate 2A–D

Lophogorgia aurantiaca Horn, 1860: 233 .

Gorgonia aurantiaca Verrill, 1864: 33 (non Gorgonia aurantiaca, Milne Edwards & Haime, 1857 ); Verrill 1866: 327.

Gorgonia (Eugorgia) mexicana Verrill, 1869: 415 .

Eugorgia aurantiaca Verrill, 1868: 410 –411; Bielschowsky 1918: 45; 1929: 182–183; Kükenthal 1924: 346; Stiasny 1951: 63 –65; Sinsel-Duarte 1991: 30; Harden 1979: 122.

Eugorgia forreri ? Studer, 1883: 6, syn. nov.

Eugorgia forreri Bielschowsky 1918: 44 ; 1929: 178–179; Kükenthal 1924: 345; Harden 1979: 125.

Material examined. Lectotype, here designated: YPM 2269, dry fragment, Sinaloa, Mazatlán, G.H. Horn, (probably the type series collected before 1860 by Horn), no further data.

Paralectotype: YPM 389, same data as the lectotype.

Other material: MEXICO: MCZ 61014, 36185; YPM 8715, dry, La Paz, no depth given, J. Pedersen, 1867–70; YPM 397, dry, La Paz, 11–15 m, W.B. Rich, 1863; YPM 1707, dry, Acapulco, no depth given, A. Agassiz, 1859–1860; MNHN oct.0000-0549, dry, Baja California, no depth given, M.L. Diguet, 1897; MNHN oct.0000-0554, oct.0000-0559, dry, Mazatlan, no depth given, M. le Général Rollin, 1864. PANAMA: USNM 1016591, dry, west coast of Panama, E. Deichmann, no further data; USNM 33603, dry, no further data. Without data: MNHN oct.0000-0552, dry, original label from RMNH; MNHN oct.0000-0551, dry, original label from RMNH.

Description. The examined specimens reach up to 32 cm in height and 38 cm in width. The lectotype is a fragment 8 cm in height and 3 cm in width, and the paralectotype is a smaller fragment 3 cm in height and 1.5 cm in width (Plate 2A, branch and detail). Colonies form densely branched fans (Plate 2B, C). Main stems are 4–6 mm in diameter, compressed, and up to 2 cm long or absent, so the branches emerge directly from spreading holdfasts. Main branches are compressed and divergent, 2–3 mm in diameter, branching irregularly pinnate, the pinnae 1–2 mm in diameter and they are irregularly arranged and not close together (Plate 2C). Several of the pinnae rebranch giving off secondary pinnae, some are pseudoanastomosed (anastomosis of the coenenchyme, not of the axes). Unbranched terminal twigs are blunt, and reach up to 3 cm in length. Polypmounds are prominent, with bilabiate apertures, and reach up to 1 mm in diameter. The polyp-mounds are placed in irregular longitudinal rows along the branches, and do not crowd the surface (Plate 2C). Colonies are dark orange, streaked with bright yellow on the branches and with yellow rings on polyp-mounds. The main branches have numerous yellow, longitudinal grooves that are more evident on thick branches. Sclerites of the coenenchyme are red and yellow (Plate 2D). In the lectotype, they are mostly double discs reaching up to 0.07 mm in length, and 0.05 mm in width ( Fig. 6 ). Capstans are about the same size with complex tubercles at the ends. Spindles reach up to 0.11 mm in length and 0.045 mm in width, with 3–5 whorls of warty tubercles, with mostly acute ends; and crosses about 0.06 by 0.06 mm ( Fig. 6 ). No anthocodial sclerites were obtained in the samples examined. Size and shapes of the sclerites in the examined specimens are as in the lectotype.

Distribution. Sinaloa, type locality; La Paz, Acapulco, Cabo Pulmo ( Sinsel-Duarte 1991) and Panama ( Table 4).

Remarks. This species was described by Horn (1860) probably based on large specimens, but all that seems to have remained are the two fragments, YPM 2269 and 389, which were given to Verrill (YPM) by Horn from the Academy of Natural Sciences of Philadelphia. The original specimens collected by Horn were supposedly deposited in the Academy of Natural Sciences of Philadelphia, but we could not locate them. Horn reported an unknown locality of collection, but Verrill (1868) indicated that it was Mazatlan, as is the case for Leptogorgia clavata ( Horn, 1860) ( Breedy & Guzman 2007) , and Pacifigorgia englemanni ( Horn, 1860) ( Breedy & Guzman 2002) .

Two specimens of E. aurantiaca from Mazatlan found in the MNHN (oct.0000-0554, oct.0000-0559) were identified by Valenciennes in 1864 as Gorgonia bicolor , however this species name was never published.

Studer (1883) identified a collection from the Gulf of California, La Paz and Mazatlan given to him by Alfonse Forrer. He reported 15 gorgonian species, among them three species of Eugorgia : E. aurantiaca , E. bradleyi , and the newly described E. forreri , with a question mark, with neither illustrations, nor holotype designation. We could not locate any syntypes of this species for examination, but Studer’s description matches E. aurantiaca . For these reasons we herein synonymise E. forreri . Some specimens in the California Academy of Sciences identified as E. forreri do not match Studer´s description. They probably constitute new species but were found too late for inclusion in this work.

Figures

FIGURE 6. Eugorgia aurantiaca (YPM 2269), coenenchymal sclerites.