Eugorgia multifida Verrill, 1870

Breedy, Odalisca, Guzman, Hector M. & Vargas, Sergio, 2009, A revision of the genus Eugorgia Verrill, 1868 (Coelenterata: Octocorallia: Gorgoniidae), Zootaxa 2151, pp. 1-46 : 22-24

Eugorgia multifida Verrill, 1870

Figure 10 , Plate 6A–D

Eugorgia multifida Verrill, 1870: 554 –555; Bielschowsky 1918: 45; 1929: 179–180; Kükenthal 1924: 345; Harden 1979: 126 –127.

Material examined. Syntype series: YPM 2257, dry, Acapulco, A. Agassiz, no further data; YPM 2257a–b, 4605, dry, Mazatlan, J. Dickinson, no further data; USNM 49368; YPM 4069, 8715, dry, La Paz, 11–15m, J. Pedersen, 1867-70. Other material: CASIZ 0 73819, ethanol preserved, NW Islote Blanco, SW Isla Danzante, Baja California, 4.5–12m, G.C. Williams, 22 July 1990; CASIZ 100846, ethanol preserved, Isla Cerralvo, Rock Islet Carpenteria, Baja California, 15 m, Ray (Chubb) Keys, 2 May 1976; CASIZ 103207, ethanol preserved, S Isla Danzante, off Candeleros, 24 m, Ray (Chubb) Keys, 1st May 1975; CASIZ 103393, ethanol preserved, 2 Km N off Boca del Tule to Arena Blanca, Baja California, 30 m, no collector, 26–27 April 1976.

Description. The examined specimens reach up to 35 cm in height and 35 cm in width. Colonies are flabelliform and densely branched. The main stem is up to 5 mm in diameter, compressed, and up to 2 cm long. It divides at the base into several, large, irregularly divergent branches or the branches arise directly from the holdfasts. Main branches are compressed, up to 4 mm in diameter, branching irregularly pinnate; the pinnae are 1–1.5 mm in diameter, short, and closely arranged (Plate 6A). They commonly rebranch giving off secondary and tertiary pinnae. Unbranched terminal twigs are blunt, and reach up to 1 cm in length. Polyps are distributed in irregular lateral bands along the branches, not very close and more distant on the thick branches, and separated by marked longitudinal grooves. Polyp-mounds are prominent, and reach up to 0.5 mm in diameter, with small apertures bordered by bright yellow sclerites (Plate 6B). Polyps have weak points-like arrangement, a few anthocodial sclerites at the base of the tentacles. Colonies are dark orange to bright red uniformly or streaked with bright yellow sclerites that blend with the red sclerites on the surface of the branches. Sclerites of the coenenchyme are red, yellow, and bicoloured (Plate 6C). They are mostly double discs reaching up to 0.07 mm in length, and 0.05 mm in width (Plate 6C, Fig. 10 ). There are also a few capstans about the same size with complex tubercles at the ends, and spindles reaching up to 0.13 mm in length, and 0.05 mm in width, with 3–6 whorls of warty tubercles (Plate 6C, Fig. 10 ). Furthermore, crosses are present about 0.06 by 0.06 mm. Anthocodial sclerites were only found in preserved specimens, they are orange, flat rods, up to 0.08 mm in length, and 0.027 mm in width, lobed with serrated margins (Plate 6D). Other colonies examined agree in all aspects with the syntypes. In preserved specimens polyps are colourless, and the colour of the colonies does not change after preservation. The illustrated specimen, syntype YPM 4605, measures 14.5 cm in height and 29 cm in width, with the small remains of a conic holdfast (Plate 6A–B).

Distribution. La Paz, Baja California, Mazatlán, Acapulco ( Table 4).

Remarks. Eugorgia daniana , E. aurantiaca , and E. multifida are very similar in their type of branching and their prominent polyp mounds. However, E. multifida is separated from this group by the compact, thick and short branchlets of the colony. Eugorgia aurantiaca is very similar to E. daniana , but the latter has the branches and branchlets more closely placed, thinner and less compressed with smaller polyp mounds. Eugorgia aurantiaca differs from the other two species in the presence of yellow rings on the polyp mounds, and in the distribution of the polyps that is more organised in two to four rows than in E. daniana or E. multifida , where the distribution is in multiple rows. Additionally, the double discs in E. daniana are sharper than in the other two species, and smaller spindles were found in E. aurantiaca (Table 1).

Figures

FIGURE 10. Eugorgia multifida (YPM 4605), coenenchymal sclerites.