Alcyonium

Williams, Gary C., 2013, New taxa and revisionary systematics of alcyonacean octocorals from the Pacific coast of North America (Cnidaria, Anthozoa), ZooKeys 283, pp. 15-42 : 21-24

Alcyonium sp. indet. Figures 5-6

Synonomy.

Alcyonium sp. Williams (2007: 184-185, 188); Williams and Lundsten (2009: 1078).

Material examined.

CAS 179450, Canada, British Columbia, Weynton Passage, Plumper Group of islands, Plumper Island, (50°35.501'N, 126°47.997'W), 20 m depth, 10 November 2009, collector: N. McDaniel, one whole colony. CAS 173217, Canada, British Columbia, Strait of Juan de Fuca, Swordfish Island (48°18'36.4"N, 123°34'58.4"W), 6 m depth, 28 September 2009, collectors: C. Blondeau, T. Hill, R. Van Hall, one whole colony, abundant in underwater tunnel with dynamic surge. CAS 029138, U.S.A., Alaska, Arctic Ocean, near Point Barrow, 44 m depth, 29 July 1951, collector: J. Bohlke on R/V ”Ivik”, two whole colonies.

Taxonomic assessment.

Alcyonium sp. indet. is known from the west coast of North America from Alaska south to British Columbia and California, and has been referred to as Gersemia rubiformis , Capnella rubiformis , or Eunephthya rubiformis in numerous publications (examples: Madsen 1944; Ofwegen 2012). These binomens are based on the entry Lobularia rubiformis by Ehrenberg (1834: 282). All previous references that referred to the original author of the species have noted Ehrenberg (1834) as the original source. However, on page 282 of this work, he notes that Pallas was the original author. This fact apparently has eluded the attention of subsequent authors, both in print and in electronic sources as well. Ehrenberg does not identify the date of Pallas’s description, but it is known that Peter Simon Pallas published works on zoophytes and corals between 1766 and 1798 ( Bayer 1981a). Ehrenberg also notes the locality of Lobularia rubiformis as "Mari septentrionali" (= Northern Sea). Needless-to-say, this is ambiguous and could serve to describe the North Atlantic, the Arctic Ocean, or all northern seas including the North Pacific. The name Gersemia rubiformis has been applied to a species of soft coral that is reported to occur in polar to temperate regions of the Arctic Ocean and the northwest Atlantic Ocean from the eastern Canada south to North Carolina ( Ofwegen 2012b). It has also been reported from the North Pacific Ocean from Alaska south to California and west to Russia ( Williams et al. 1987; Ofwegen 2012b).

In addition, there are other ambiguous details that are relevant here. Ehrenberg’s 1834 paper is dedicated to the corals of the Red Sea, but he lists Lobularia rubiformis as inhabiting the "Mari septentrionali." The genus Lobularia is a synonym of Cladiella , a zooxanthellate Indo-Pacific genus that is distributed in the Red Sea as well as much of the Indo-West Pacific ( Fabricius and Alderslade 2001). The genera to which this species has been identified in the literature represent two different soft coral families, the Alcyoniidae and the Nephtheidae . My examination of western North American material reveals that the species has small, completely retractile polyps and a polyp arrangement that is lobate rather than catkin-like (even though there may be few to no polyps on the lower parts of the expanded lobes). In addition, the northeastern Pacific material (Figure 5) exhibits morphological similarities to other species of Alcyonium , as previously described and illustrated ( Verseveldt and Ofwegen 1992; Casas et al. 1997; Ofwegen et al. 2007). The general appearance of the scIerites of Alcyonium sp. indet. (Figure 6) are consistent with other species of the genus as well. I therefore here align the species to the Alcyoniidae , rather than the Nephtheidae .

Recent molecular phylogenetic evidence shows that there are two species included in Gersemia that nest in the genus Alcyonium , rather than with other nephtheids ( Breedy et al. 2012: 357). In light of this, future research may show that other species previously allocated to Gersemia may in fact belong to Alcyonium . It is not known if a type specimen of Lobularia rubiformis was ever designated. From the aforementioned, it is here considered that the Pacific coast material cannot justifiably be ascribed to Gersemia rubiformis and the validity of that species cannot be determined at present. Because of this, the Pacific coast species is considered as an unidentified species of the genus Alcyonium Williams 2007: 184-185, 188; Williams and Lundsten 2009: 1078). It is evident that a taxonomic revision and determination of the validity of Gersemia rubiformis is necessary, and that molecular studies of samples from various populations in the Atlantic, Arctic, and Pacific Oceans may provide a clearer understanding regarding taxonomic status.