Adelogorgia phyllosclera Bayer, 1958

Horvath, Elizabeth Anne, 2019, A review of gorgonian coral species (Cnidaria, Octocorallia, Alcyonacea) held in the Santa Barbara Museum of Natural History research collection: focus on species from Scleraxonia, Holaxonia, Calcaxonia - Part II: Species of Holaxonia, families Gorgoniidae and Plexauridae, ZooKeys 860, pp. 67-182 : 67

Adelogorgia phyllosclera Bayer, 1958 Figures 1, 2A, B, 3 A–C

Adelogorgia phyllosclera Bayer, 1958: 46-47; figs 3 a–f, 4a, b, 9b, c. Breedy and Guzmán 2018: 330-333.

Type locality.

USA, California, La Jolla, South of Scripps Institution, La Jolla Canyon, 30-33 m.

Type specimens.

Holotype USNM 50186; [dry]. Paratypes listed under "other material" in "Appendix 1: List of material examined" for this species.

Material examined.

~26 lots (see Appendix 1: List of material examined). All specimens at USNM were examined for comparison purposes.

Description.

Colony (Figure 1) heavy; bushy to fan-shaped, branching strictly in single plane, particularly in young colonies (≤ 20 cm height), but with branches occasionally growing irregularly as colony gets older (up to 0.6 m in height, usually less than 0.3 m); branching dichotomous, irregular and lateral, not pinnate (Figure 2A), with knobby to smooth branches. Color of live colony red or orange-red, polyps yellow to yellow-orange; axis slender, orange. Dry specimens brilliant red, rusty red, maroon-rust to black. Branches 2.0-4.5 mm in diameter, ascending into a meandering, sinuous form; terminal branches short (3.0-4.0 cm), slightly swollen at distal ends (Figure 2B). Trunk diameter measures up to ~6.0 mm. Axis in dead/dry specimens, within all branches of older part of colony, black, smooth, without conspicuous striations; in branches of younger portions of colony, maroon. Outer layer of axis abundantly loculate, texture of axis weak, flexible in terminal portion of branches, rather brittle in base area. Polyps with weak operculum, composed of two to four curved spindles in every segment, arranged en chevron; sclerites in polyps not arranged transversely, not forming collaret. Polyps able to retract down to surface or upper marginal edge of low to moderate calyces, these moderately elevated as low bumps off branch surface (0.5-0.8 mm tall, 1.2 mm across), situated some 2.0-2.5 mm distance apart, distributed over entire surface of all branches; margin of calyces not dentate. Sclerites (Figure 3) of polyps straight or curved rods, sculptured with simple conical warts, arranged en chevron, two to four sclerites at base of each tentacle. Coenenchyme spiculation in two layers; layers determined by shape of sclerites seen in each. Exterior layers of coenenchyme with stout capstans (0.1 mm), and spindles (0.2 mm); (latter more common), some less commonly present as having leaves or scales over one surface; few appear as leaf clubs. Numerous sclerites with sculpturing on one side modified into leafy projections (double-discs) as seen in Figure 3B (appear occasionally as sclerites analogous to disc-spindles of Eugorgia ); in many cases, sclerites (0.1-0.15 mm) strongly characteristic of this form; proportion of leafy sclerites to ordinary ones in outer layer of coenenchyme varies only slightly. Ordinary ones are most abundant, while leafy ones, though sometimes rare, are always present. Axial sheath (interior layer of coenenchyme) contains symmetrical spindles (0.16 mm) only; no capstans, clubs or leafy scales. Sclerites of outer layer red; of inner layer nearly colorless.

Etymology.

The root phyllo- (Greek) = leaf; sclero- (Greek) = hard scale. Species is unusual in the leafy appearance of one sclerite type, a key characteristic in identifying the species. However, Bayer gave no explanation for either genus or species names.

Common name.

Chuck’s gorgonian; Orange gorgonian; Shady-leafed gorgonian; Hard-leaved gorgonian; Hidden gorgon (these names appear in a variety of field/diving guides for the area such as Gotshall 2005, Kerstitch and Bertsch 2007).

Distribution.

Based on collection location data, from Upper Baja, California to southern California. Generally known from La Jolla area of southern California. One specimen from Catalina Island, Bird Rock, SBMNH 51252 (one of several from Santa Catalina Island), indicates this species does range a bit north of La Jolla, California.

Biology.

Commonly encountered in southern California in kelp beds; depth range of 20-300 m ( Gotshall 2005). An anecdotal note (J Ljubenkov, penciled notation on a species list) stated: " Adelogorgia phyllosclera is a deep water form; it is a major deep water gorgonian and replaces Muricea on sewage pipes" (verified by staff of LACSD and OCSD). Two specimens, USNM 50186 and SBMNH 422894 (Point Loma), support numerous epizootic anemones (perhaps Epizoanthus Gray, 1867). On others, a flat, grayish incrustation (perhaps bryozoan) can be seen. Some balanoid barnacles are present over the surface of some specimens examined, in the form of prominent cysts ( “galls”) on the branches, which protrude out from the axis through a coenenchymal covering. One specimen (SBMNH 422893) harbors a small brittle star, wrapped around a portion of the main trunk. No zooxanthellae present in the tissues, particularly true of USNM 50186; specimen examined for their presence by Bayer.

Remarks.

Among the eight to ten specimens that Bayer examined in 1958, there appeared to be three main areas that showed variation: thickness of branches, development (size) of the calyces (if present), and proportions of different sclerite forms (those with leafy sculpturing as compared to common spindles/capstans) (Bayer unpublished ms 7, Cairns 2009). Specimens at SBMNH do illustrate variation in branch diameter. Terminal branches range in diameter from 2.0-4.5 mm. Branches with smallest diameter have very distinct, prominent calyces, arising conically from their base, but thicker branches have less conspicuously prominent calyces, actually coenenchymal mounds appearing as low bumps; polyps fold into simple openings that appear as pores. One specimen at NMNH, USNM 50187, is of an extreme form; some of the branches are quite slim, bearing very pronounced calyces. It became clear that similar variations were not of taxonomic significance. Other more slender specimens exhibit a wide range of variation in branch diameter.

Most field/diving guides imply that this species is fairly contained within, and to, the region of La Jolla, California. Several of the SBMNH specimens argue against this; it appears that this particular species ranges a bit further south (upper/lower Baja) than had been previously reported. Three lots examined and confirmed correct as to their genus identification (at least) implied either: 1) a range that extends further south and/or 2) the presence of several other species, including Adelogorgia telones Bayer, 1979, and one or more of the species recently described by Breedy and Guzmán (2018), in the collection. As to potential range of distribution, Bayer (1979) made the following comment in his description of A. telones : "Although it ( A. phyllosclera ) seem(ed) to be rather common in the vicinity of La Jolla, collections made farther to the south, in Baja California, by the same team of divers, (did) not include it ( A. phyllosclera ). Neither does it occur in other collections from Baja California and the Gulf of California taken by diving or dredging, nor in collections obtained by the US Fish Commission steamer ‘Albatross’ by dredging and trawling at many localities along the coast of Central America and South America". There are, however, several specimens in the SBMNH collection taken from northern Baja California that clearly appeared to be this species (see Appendix 1: List of material examined). Further sightings/collections would help to confirm this species’ total range (where it may either transition to A. telones , or other recently discovered species, or has a definite southern limit, with A. telones and other species then appearing some distance further south). In the examination of specimens from California locations, and those from the Galápagos Islands, in the SBMNH collection, the distinctive differences that would separate species were not clear; all specimens, with one exception (completely bleached, SBMNH 422891 from Santa Cruz Island, Galápagos Islands), are the distinctive red color of this species. A. telones , by contrast, is typically either yellow or white ( Bayer 1979, Breedy and Guzmán 2018). Bayer (1979) stated that, in a comparison of the two species, A. phyllosclera has: 1) branching that is more crooked and open, 2) polyps that form distinctly hemispherical or blunt-conical calyces (as opposed to calyces being inconspicuous or not really present at all), and 3) sclerites somewhat larger, with double wheels/discs somewhat different in shape along with being more elaborately sculptured. Based on the coloring of specimens (with one exception) in the SBMNH collection, along with Bayer’s (1958) discussion of variation in characters within this species, there are unanswered questions regarding distribution of this species and the potential for several other species, as represented in the SBMNH collection. Both A. phyllosclera and A. telones are accepted species in the WoRMS Data Base ( Cordeiro et al. 2018a), along with three others.