New taxa and revisionary systematics of alcyonacean octocorals from the Pacific coast of North America (Cnidaria, Anthozoa)

Abstract A taxonomic assessment of four species of octocorals from the northeastern Pacific Ocean (British Columbia to California) is provided. Included here are a new species of clavulariid stolonifieran Cryptophyton, a new species of the nephtheid soft coral Gersemia, an undetermined species of soft coral in the genus Alcyonium that has been referred in the literature by several other names, and a new genus is named for a plexaurid sea fan originally described in the Indo-Pacific genus Euplexaura. Discussions are included that compare the species to related taxa, or provide revisionary assessments.


Introduction
reviewed the present status of knowledge of octocorals in the major geographical regions of the world and established four categories representing broad levels of taxonomic knowledge -essentially complete, moderately well-known, poorly transverse platforms absent. Anthocodial armature absent. Sclerites of stolons and anthosteles 0.06-0.10 mm in diameter, mostly spiny balls or stellate bodies with projecting processes in three dimensions. Type material. Holotype. CAS 177194. North America, U.S.A., California, San Diego County, San Diego, Point Loma, 32°42'N, 117°15'20"W, 12 February 2006, collector: Jeff Goddard, one specimen wet-preserved in 95% ethanol. Habitat and distribution ( Figure 19): Under a boulder in the low rocky intertidal zone at the type locality.
Etymology. The species is named for Jedediah Strong Smith, American trailblazer and cartographer, who explored vast regions of western North America between 1822 and 1831, and along the Pacific Coast, including San Diego in December of 1826 (Brooks 1977) -the area of the type locality of the new species.
Description. Colonial morphology ( Figures 1A, 2). The holotype consists of approximately eighty-five polyps arising from flattened basal stolons. The stolons encrust a piece of dead cheilostomatid bryozoan, 32 mm long by 20 mm wide. The surface of the bryozoan is interspersed with several calcareous tubes of a serpulid polychaete.
The geographic range of Cryptophyton goddardi was originally known only from the type locality of central Oregon on the Pacific Coast of the United States, but has recently been extended southwards to southern California, and has been collected at seven locations (Figure 19), while C. jedsmithi sp. n. is known only from the type locality -San Diego, California ( Figure 19).  : 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). Needlessto-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).

Key to the species of Cryptophyton
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;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.
Etymology. This species is named for marine naturalist and educator Andy Lamb (Vancouver, British Columbia), who collected the type material.
Description. Colonial morphology (Figures 7B-C). The holotype measures 55 mm in length, 39 mm in width, and 35 mm in height. It is composed of dense concentrations of autozooids distributed in isolated clusters on several lobes that emanate from the stalk, which arises immediately above the basal holdfast. Each cluster usually contains approximately 5 and 15 polyps.
Polyps ( Figures 7B-C,F). The polyps are monomorphic, non-retractile, tubular in shape, and vary in length and width (4.0-7.0 mm in length and 1.5-2.0 mm in width). The width of the polyps is greatest at the distal extremities. The polyps are erect and often curve upward from their bases.
Sclerites (Figures 8-11). Coenenchymal sclerites of the polypary are primarily sharply-tuberculated radiates, 0.03-0.11 mm. Coenenchymal sclerites of the stalk are mostly variously-ornamented radiates and modified radiates, 0.03-0.12 mm long. Polyp wall sclerites abundant, uniformly and densely-distributed, 0.03-013 mm in length, mostly variably-shaped radiates and rods with a few irregularly-shaped elongate forms and crosses. Tentacle sclerites densely and uniformly distributed (not arranged en chevron), mostly radiates and rods, although a few club-shaped or approach torch-like forms are also present.
Color ( Figures 7A-D,E). Colony color is pink to reddish in life, often with orange oral discs. Colonies are uniformly cream-white in color when preserved in ethanol.
Differential diagnosis. The only other species known in the genus Gersemia from the Pacific Coast of North America is Gersemia juliepackardae Williams & Lundsten, 2009. Although coenenchymal sclerites of the two species are predominantly eight radiates, G. juliepackardae and G. lambi sp. n. differ markedly in surface feature characters. Those of G. juliepackardae are narrow with slender medial waists and relatively rounded tubercle tips (Williams and Lundsten 2009), while those of G. lambi sp. n. are broad with wide medial waists and more acute tubercle apexes (Figures 8-11).
This species is distributed from Washington to southern California, while G. lambi is known from southern Alaska to British Columbia. The two species differ markedly in their bathymetric distributions. Collected material of Gersemia juliepackardae is recorded between 888 to 1600 meters in depth, although video images record the species from 520-2034 meters (Williams and Lundsten 2009). Gersemia lambi sp. n., on the other hand, is known at present only from a depth range of 9-20 meters.

Key to the species of Gersemia from the west coast of North America
1a Alcohol-preserved polyps cylindrical, straight, 4.5-5.5 mm long by 1.  Kükenthal, 1913. Etymology. The generic name is derived from the Greek chroma (color), and the gorgonian generic name Plexaura, in reference to the vivid color of the colonies.
Systematics and phylogenetic assessment. The genus Euplexaura ( Figures 12D,  18) is an Indo-Pacific genus (eastern Africa to the central Pacific) of 37 named species (Ofwegen 2012a), with the number of valid species not determined. The surface coenenchyme contains numerous robust ovoid to subspherical sclerites (Fabricius and Alderslade 2001). All sclerites are colorless. Since E. marki differs in these several respects to the genus to which is was originally described, a new genus is here named to accommodate it.
A comparison is also warranted between Chromoplexaura and two plexaurid genera that share some superficial similarities -Thesea with 31 described species from the Atlantic Ocean (Deichmann 1936: 110;Humann and DeLoach 2002: 78;Ofwegen 2012d), and Swiftia with 14 described species from the Atlantic and eastern Pacific (Deichmann 1936: 185;Goldberg 2001: 100;Humann and DeLoach 2002: 65;Ofwegen 2012c). It is yet to be determined if the Pacific species presently allocated to Swiftia do indeed belong to that genus or another one. The polyps of Swiftia emanate from calyx-like protuberances, and both Thesea and Swiftia have a preponderance of narrow/elongate to robust spindles. The sclerite complements of both genera are composed mostly of spindles with few to no radiates present. On the other hand, the sclerite complement of Chromoplexaura is comprised primarily of radiates and variably-shaped spindles.
Forty five genera of the holaxonian family Plexauridae are currently considered valid (Williams and Cairns 2011). Molecular phylogenetic studies have shown that the resolution necessary to produce a molecular phylogeny of the octocorals is lacking at present, due to slow rate of mitochondrial gene changes and a paucity of markers necessary to distinguish some taxa. Regarding future research, it is anticipated that ITS2 sequence data will produce improvements regarding better resolution and more credible results (McFadden et al. 2006, McFadden et al. 2010, Wirshing et al. 2005. Currently, the evidence based on molecular data does not support the family as being a monophyletic one, but rather has shown many genera dispersed throughout  richly-populated phylogenetic trees, and do not exhibit close affinities as a group. In some cases, plexaurid genera have even appeared associated with genera in other families (McFadden et al. 2006;Wirshing et al. 2005). At present, it is therefore not possible to produce a plausible topology of phylogenetic relationships for such genera as Euplexaura, Swiftia, Thesea and Chromoplexaura gen. n.    Description. Colonial morphology (Figures 12-13): The predominantly proteinaceous central axis has a hollow core. The main stem above the holdfast varies from 50-120 mm in length. The ultimate branches measure 10-115 mm in length by 2.5 -4.0 mm wide. The distal extremities are acute to rounded and often slightly swollen compared to the uniform width of the rest of the branches.

Key to the genera Chromoplexaua and
Polyps (Figures 12-13). Most of the polyps are fully retractile and form low rounded to hemispherical protuberances that are distributed on all sides of the branches. Some polyps are partially exserted and are <1.0 mm in width. Autozooid walls with eight longitudinal rows of densely-set, more-or-less en chevron sclerites that give rise to narrow points in the middle of each tentacle.
Color (Figures 12-13). The color of the colonies is similar in life or preserved, the coenenchyme is uniformly-colored orange-red to vivid red, while the exsert polyps are white ( Figure 11E). The coenenchymal sclerites are red-orange, while the polyp wall and points sclerites are colorless.
Distribution ( Figure 19): Central Oregon to southern California; 9 to at least 90 m depth.
Biology and associated species. Several of the colonies in lot 096746, have enlargements on the branches that resemble gall-like growths, which contain epizoic barnacles of the genus Conopea (pers. comm., R. Van Syoc, California Academy of Sciences).

Discussion and conclusion
In spite of the fact that the marine fauna of the west coast of the United States is relatively well known with a plethora of marine laboratories dotting the coast, as well as an abundance of well known and excellent manuals and field guides describing the fauna (Morris et al. 1980;Ricketts and Calvin 1985;Niesen 1994;Carlton 2007;Gotshall 2005;Lamb and Hanby 2005), the octocoral fauna is still largely only minimally studied. Perhaps the main factor responsible for this is that although a number of species have been described since the late 19 th and early 20 th centuries, the essential revisionary systematics necessary for ascertaining valid taxa, has been unfortunately ignored. As an example, the generic designation (Euplexaura) for a common plexaurid gorgonian from California and Oregon has been misapplied for the past century . The new genus Chromoplexaura is here named to provide a valid designation for the binomen C. marki.
In addition, two new species of octocorals are here described from recently collected material in the intertidal zone of southern California and in shallow subtidal regions of British Columbia and southern Alaska.