Eugorgia beebei, Breedy, Odalisca, Williams, Gary C & Guzman, Hector M, 2013

Breedy, Odalisca, Williams, Gary C & Guzman, Hector M, 2013, Two new species of gorgonian octocorals from the Tropical Eastern Pacific Biogeographic Region (Cnidaria, Anthozoa, Gorgoniidae), ZooKeys 350, pp. 75-90 : 76-79

Eugorgia beebei sp. n. Figs 1-3

Eugorgia rubens var. beebei (species name suggested by E. Deichmann in a museum label, unpublished)

Material examined.

Holotype. CASIZ 75783, ethanol preserved, Los Frailes, Baja California sur, México, 52 m, coll. R. Adcock, 18 June 1979.

Paratypes. MCZ 36106, dry, Paita, Piura, Perú, no more data available. USNM 56879, ethanol preserved, El Alto, Piura, Perú, 1860-1815 m but depth data dubious (F. M. Bayer’s note on label: 'specimen probably from previous shallow station’), Anton Bruun Cruise, 18B, Sta. 766, 4°10'S, 81°27'W, 9 September 1966.

Type locality.

Baja California sur, México.

Diagnosis.

Ascending colony sparse growing, branching irregularly pinnate, and multiplanar, subdividing up to 11 times, some pseudo-anastomosis present. Prominent polyp-mounds up to 0.70 mm tall, dome-shaped, arranged irregularly, and closely placed on branchlets, and very distant on thick branches. Colony and sclerites white. Spindles and disc-spindles up to 0.14 mm in length, double discs up to 0.07 mm long, and 0.05 mm wide. Anthocodial rods absent.

Description.

Holotype 24 cm tall, and 20 cm wide, ascending, sparse growing, (Fig. 1A). Branching irregularly pinnate, and multiplanar, several pseudo-anastomosis occurs in branchlets and branches (Fig. 1 A–B). Main stem 4 mm diameter at base, slightly compressed, and short, about 80 mm long arising from a fragment of holdfast, 0.6 mm diameter. Main stem gives off several branches and stumps. The three main branches, 3.0-4.0 mm in diameter, emerging at angles of 45-90°and producing secondary branches subdividing and giving off thin branchlets, up to 2.5 mm diameter, including polyp-mounds. Branchlets irregularly arranged, separated 5-16 mm, and giving off 2 or 3 lateral, secondary branchlets, of same thickness and arrangement. Colony branching up to 11 times. Unbranched terminal twigs blunt, and reaching up to 50 mm long (Figs 1 A–B). Polyp-mounds prominent, up to 0.7 mm height and 1 mm in diameter, dome-shaped, with slit-like apertures, arranged irregularly, close together along the branchlets, and very distantly distributed or absent along the thick branches (Fig. 1B). Holdfast devoid of polyps. Colony white (Fig. 1 A–B). Sclerites of coenenchyme white, mostly double discs (Fig. 1C). Spindles and disc-spindles, up to 0.14 mm long and 0.04 mm wide, with 4 or 5 whorls of warty tubercles, the ends mostly blunt (Fig. 3A). Double discs up to 0.07 mm long, and 0.05 mm wide (Fig. 3B). Crosses about 0.08x0.06 mm, scarce on samples (Fig. 3C). No anthocodial sclerites present in the samples.

Variability.

Paratype MCZ 36106 reaches up to 34 cm tall, and 31 cm wide, the main stem 0.7 mm diameter, slightly compressed, and short, about 1.0 cm long arising from an oval holdfast 3.2 cm diameter, and 0.2 cm thick (Fig. 2 A–B). Sclerites as in the holotype (Fig. 2C). The other examined specimens are smaller, but very consistent in all aspects with the holotype.

Discussion.

The morphology of the colony, i.e., irregular-pinnate branching and prominent polyps, immediately segregates the new species from the ampla-group, and suggest a similarity with daniana-, rubens- and siedenburgae-groups. Eugorgia beebei and Eugorgia siedenburgae differ from the species in the daniana-group, including Eugorgia mutabilis sp. n. (described below), firstly, in the colony growth, which is sparse and ascending in Eugorgia beebei sp. n. but bushy and profuse in Eugorgia siedenburgae , not flabellate as it is in the daniana-group species. Secondly, it differs in the branching patterns because branchlets in the daniana-group form flat pinnate fronds with pinnae projecting in the same plane. That is not the case in Eugorgia beebei and Eugorgia siedenburgae where the secondary branchlets stick out in several, irregular planes.

Eugorgia siedenburgae and Eugorgia rubens form monospecific groups, they differ especially in the colony growth. The rubens-group have pink, sparse and laterally branched colonies, and the siedenburgae-group, have bushy, bicolored colonies ( Breedy and Guzman 2013).

Eugorgia beebei and Eugorgia siedenburgae are very similar in sclerite content (Table 1), but they are different especially in the growth form and in the color. The conspicuous bushy colony immediately distinguished it from Eugorgia beebei ; additionally, Eugorgia beebei has thicker branches and branchlets than Eugorgia siedenburgae ; the polyp mounds are pointed and higher in the latter, and are more rounded in Eugorgia beebei . Branchlets in Eugorgia beebei are longer than in Eugorgia siedenburgae (Table 1).

Remarks.

We found the paratype in the MCZ (36106), labelled in Elisabeth Deichmann’s handwriting (Ardis Johnston, pers. comm.) as a variety of Eugorgia rubens , however, she certainly had not published anything on this genus, thus the variety or the species was never established. The specimen was part of an MCZ public exhibition, the only data we have are the locality. It is probable that this specimen examined by Deichmann came from the Zaca expedition of 1937 and 1938. We do not consider Eugorgia beebei as a variety of Eugorgia rubens because they differ in the traits that have been shown to be informative to separate species in the genus: color, branching pattern, colony growth and sclerite content (see Table 1), as mentioned above.

Etymology.

This new species of Eugorgia is named for explorer/naturalist William Beebe (1877-1962) who studied the marine fauna at numerous locations along the west coast of Central America from Mexico to Columbia during the Templeton Crocker Zaca expedition between 1937 and 1938. Beebe subsequently wrote the book, Book of Bays, which chronicles the five month expedition ( Gould 2004).

Distribution.

Presently known from Piura, Perú and Baja California, but it is very likely that it exist along all along the geographic range. The depth range is 50-60 m, it is possible the range could extends deeper, but not as deep as reported for paratype USNM 56879, which is probably a mistake, as was remarked by F. M. Bayer (former USNM curator).