Muricea californica Aurivillius, 1931

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

Muricea californica Aurivillius, 1931 Figures 39A, B, 40 A–D, 41 A–C

? Gorgonia plantaginea Valenciennes, 1846: pl 15 (non Lamarck).

? Muricea appressa Verrill, 1864: 37; 1866b: 329; 1869a: 44. Grigg 1970: xiv, 20, 25, 207; 1977: 280.)

? Muricea appressa flavescens Verrill, 1868a; 1869a: 446 (? nec Verrill, 1864: 37).

Muricea californica Aurivillius, 1931: 111-114, fig, p 113. Hardee and Wicksten 1996: 130-132. Breedy and Guzmán 2016b: 32-34.

Type locality.

North Pacific Ocean, California Channel Islands, Santa Catalina Island, Gulf of Santa Catalina, 2-27 m.

Type specimens.

Syntype USNM 44188 [wet]; Lectotype USA: Swedish Museum of Natural History 1122 [wet]. Syntype specimen was examined; a common form in California waters, often easily identified.

Material examined.

~32 lots (see Appendix 1: List of material examined).

Description.

Colony (Figure 39A) non-reticulate; up to 100 cm wide, 120 cm high, usually 60 cm or less. Loose, dichotomous, irregular branching primarily in one plane, forming heavy fan-shaped colony; some primary and secondary branches extend out of plane. Branches thick, averaging 2.0-5.0 mm in width; curve to lie parallel with main branch. Branching lateral, terminals of even thickness or tapering slightly. Outer coenenchyme mostly occluded by calyces (Figure 39B). Calyces distally open cups, erect, very elongated, prominent, conical in shape, 0.8-1.1 mm tall, 1.0-1.5 mm across, 1.0-2.0 mm apart (close together, but not overlapping), protruding 45 to 90 degrees away from branch when polyp extended (extendable to 3.0 mm). When polyp not extended, calyx lying close to and curving into stem, broad and smooth (like bracts in a partially closed pine cone). Upper lip varies, from those without sclerites to having definite lip. Calyces extend in all directions around branches. Tentacles taper at tip; bear two rows of lateral pinnules that are slightly displaced to the oral side. Color of living colony generally rusty brown; ranges from golden-brown to dark reddish orange to reddish brown to brown to dark brown. Axis reddish brown at base; becomes light yellow-brown at tips. Polyps most commonly yellow; golden orange, bright yellow, pale yellow, creamy yellow, even white; all polyps of a branch the same color. Possibility that more than one color of polyp per colony occurs (demonstrated in digital images sent to me by Mary Wicksten, and examination of specimens). Dry colonies dark rusty brown. Sclerites (Figure 40 A–D) rust red to golden-brown. Sclerites predominantly club-shaped with large, rounded spines or pointed tubercles projecting from broader, club-shaped end; other end tapering, covered with tubercles (Figure 41C). Outer coenenchyme consisting of small sclerites, to 0.5 mm long, torch-like, with processes often continuing irregularly down one side, other end tapering, covered with tubercles. Some spindles fusiform, bent very slightly in middle, or having large processes in middle projecting outward. Inner coenenchyme spindles small, fusiform, set with distinct tubercles.

Sclerites examined compared to those shown by Hardee and Wicksten (1996); there can be dense coverings of warts, but condition not seen on all sclerites; some sclerites have dense covering of warts at one end, but not at other end. On largest sclerites, warts are large, very few a bit bigger than those shown by Hardee and Wicksten (1996) for M. fruticosa . Many more of largest sclerites have flame-like teeth at one end, not down entire length of one side. In drawings and photographs examined of those believed to be, or labeled, this species, much larger tubercle bumps are seen. Regarding flame-like teeth, on some sclerites there are scattered, randomly-placed spines running down the side, but many more have flame-like teeth only coming off one end (reminiscent of a flaming torch; Figure 41C). Surface bumps can be dense, but not always, not over whole surface (true of some). For this species, stocky, dense clubs and torches very evident; overall, sclerites give impression of being a bit larger and more densely warted than those that may be from Muricea appressa . Refer to Figure 42, shown as Muricea plantaginea (Valenciennes, 1846); largest sclerites, however, not nearly as large as those seen in M. fruticosa .

Etymology.

Surmise that the name californica refers to the species type locality; no explanation for the species derivation was found.

Common name.

California golden gorgonian; California’s purple one; California rust gorgonian; Brown sea fan (so called in a variety of field/diving guides).

Distribution.

Stated as ranging from Point Conception, through Baja (Santa Maria) to the Gulf of California; range extending further south is possible. Grigg (1977) remarked that if M. californica is identical to M. appressa (See Harden 1969; Grigg 1970 for rationale), southern limit for this species is then Zorritos, Peru. From the following list of California sites, running from south to north, note depth ranges indicated. On the Mainland: Point Loma: 5-18 m; La Jolla: 3-27 m (USNM 50190, was collected at 11 m, in La Jolla, at the Torrey Pines kelp bed, 5 miles north of Scripps Institution); USNM 77286 was collected at Corona Del Mar, Newport Bay; Newport Beach: 2-12 m; San Pedro: 3-18 m; yet another at NMNH (USNM 52485) was collected along the southern coast. Islands: Coronados Islands: 5-24 m; Santa Catalina Island: 5-30 m.

Biology.

Common in kelp beds (Ricketts, 4th Ed. 1968); found at depths greater than 3 m, perhaps being one of the most common gorgonians from southern California ( Hardee and Wicksten 1996). Grigg (1977) noted it as a species seen in the rocky sublittoral zone off California at depths between one and 30 meters.

As colonies grow, they form annual growth rings in the skeleton ( Grigg 1974; Bertsch 1984). Colonies grow separately sexed, requiring 5-10 years to reach sexual maturity with a maximum longevity of ca. 50 years ( Grigg 1975). Grigg (1977) indicated that mortality could be caused by abrasion from suspended particulate matter when there are high waves, smothering by sand and by encrustation due to presence of zoanthid cnidarians Savalia lucifica (Cutress & Pequenat, 1960) and Epizoanthus induratum Cutress & Pequenat, 1960. On specimens of Muricea (potentially this species) located on Shale Reef, between Corona del Mar and Laguna Beach, Savalia lucifica was found (a wet SBMNH specimen, as yet uncataloged). As well, SBMNH 422359 has a heavy growth of some form of epizoanthid. Presence of the colonial anemone Corynactis californica (Carlgren, 1936) may also be an important source of mortality.

Satterlie and Case (1978) used this species extensively in studies on the neurobiology of gorgonian coelenterates, which they obtained locally (Santa Barbara area, at depths of 4-11 m). In a study done by Lissner and Dorsey (1986), it was noted that while this species was common around the Channel Islands and rocky areas of the mainland, it was conspicuously absent on the Tanner and Cortes Banks, and on the Santa Rosa-Cortes Ridge. In an anecdotal notation made by R Grigg, the reason could be that populations of Muricea species may be limited by cold water and/or poor dispersal abilities of the larvae. Grigg (1977) stated that Muricea species rarely cover more than 1% of the sea bed, where space is fully occupied.

Considering associations this species has with other organisms, Humes and Lewbel (1977) reported two species of Acanthomolgus Humes & Stock, 1972 (cyclopoid copepods) for the first time from the eastern Pacific in association with this gorgonian, from an area near La Jolla, California (Quast Reef). They indicated that these copepods are consistent members of the epifaunal community on the gorgonian, found with the gorgonian throughout the year. In association with SIO/BIC #CO 1600, there appeared to be the exoskeletal remains of either skeleton shrimp, or some other small, (and now pale) crustacean. Notes from H Bertsch (1984) indicated that sometimes the ovulid snail Simnia (Neosimnia) vidleri (GB Sowerby III, 1881) could be found eating this gorgonian; Grigg (1974) reported that the only fish known to feed on Muricea species is the Garibaldi Hypsypops rubicunda Girard, 1854 (from Clarke 1970). A specimen, from Baja, South Bay, Isla Cedros (SBMNH 422363), had very well developed acorn barnacle galls, completely overgrown and covered by healthy-looking coenenchyme; only the barnacles’ uppermost valves were visible. They appeared to have been well protected and secured to their gorgonian host. One additional specimen (SBMNH 422362) displays a bare axis at the tip of several branches; obvious barnacles are attached to these bare-tip sites. Overall, extensive organismal growth is uncommon on Muricea specimens, both wet and dry, housed in the SBMNH collection.

Remarks.

Conflicting comments about this species (comparing it with Muricea fruticosa Verrill, 1868a) have been made, particularly with regards to polyp color (Ricketts 3rd Ed, 1962; Ricketts et al. 5th Ed, 1985; Harden MS thesis 1969; unpublished pencil notation, Harden; Harden PhD dissertation 1979). In reading these it was clear to me that some identified the species by presence of yellow polyps, while others did so by white ones. There is no doubt that discrepancies regarding polyp color have carried into current identification of the species. It would be well to remember that color is hard to determine in underwater situations, in ambient light conditions, or with artificial light sources. In some of the oldest descriptions, polyp color was not always clearly stated, most likely due to collection procedures and gaps of time that ensued between collection and actual examination. There is evidence, based on my own examinations, that M. californica can have yellow or white polyps (even different colored polyps in different locations within the same colony). Confirmation came via e-mail correspondence with M Wicksten, and is stated in Hardee and Wicksten (1996: 129, 138). Divers comment that often colonies closely situated side-by-side, with basically the same colony form (thickly branched, usually in one plane), with the distinctively common brown coenenchyme, can display markedly yellow polyps in one colony and in the other (closely adjacent) one, obvious white ones. Because the colony form is so similar (perhaps due solely to current flow in the immediate area, thus an environmental condition), but polyp color so different, the two are considered (and identified) as being different species, that with yellow polyps, M. californica and those with white polyps, M. fruticosa . Yet, there is the question as to whether polyp color can be an accurate means of identification in situ, especially under low light conditions, or if color variation is genetically inherent. Questions that still require further study: 1) are colonies (yellow polyps vs. white polyps) two distinct species? 2) If so, are the two species so similar that they can hybridize? Or, 3) do two color morphs of this species exist (in southern California, at least, each with the characteristic large, planar, generally dichotomously branched colony shape)? Only an examination of sclerites, with notation made of polyp color at the time of collection, could clearly answer these questions. Channel Islands National Park, in annual fish surveys, identifies M. fruticosa as that with white polyps, while M. californica has yellow polyps. The Aquarium of the Pacific in Long Beach (via phone communication with P Clarkson, March 2003) identifies them in the same way. Unfortunately, most specimens originally identified as this species in the SBMNH collection had either sat in formalin since initial collection, had been in alcohol quite a long time, or are extremely dry; there is no color to be seen in the polyps (even if at one time they had color) and data labels usually do not indicate polyp color at time of collection. Fresh material has been requested from local sources, as they incidentally collect, to help clarify identification of this, and very similar looking species.

Allen (1976) stated that M. californica had been common at Corona del Mar in the past, and D Kushner from Channel Islands National Park (phone comm., March 2003) stated that there has been an enhanced abundance of M. californica observed in recent years at San Onofre, almost to the point of taking over, becoming quite abundant in the area. This is an area where I would expect to find this species, as it appears to be common in southern California, extending into Baja, but this growth spurt seemed a somewhat unusual event. The small collection of dry specimens (and of living specimens on public display) at the San Pedro Cabrillo Marine Aquarium holds many colonies identified as this species, collected in the surrounding local area and off the southern California Channel Islands.

Coloring of actual sclerites was often of little help, but observation of sclerite size and shape was crucial. Some of the specimens identified originally as M. californica (and for that matter, some identified as M. appressa ) were actually the typical variant of M. fruticosa , but because of condition of colony, method of preservation and transitional sclerite forms, it was initially difficult to clearly separate the species; calyx appearance was used as well, but again, groupings into distinct clusters was not always easy/clear. There was inclination to think that some specimens, listed as M. californica (likely because of overall colony shape), but from far more southern (Mexican or even Central American) collection locations, might actually be M. appressa or M. fruticosa . Without fresh material (having specific data location, observation of polyp color recorded, along with more extensive and careful extraction and preparation of the large and jagged sclerites, so as not to break them or break off the teeth), can these Muricea specimens be confidently assigned a species name. As Muricea californica seems the most common form, those listed in the Appendix 1 (List of material examined) are listed as M. californica , unless it was very clear, based on calyx appearance and sclerite form/size, that they were another species. Examination of recent, locally collected colonies (SBMNH Sea Center, Aquarium of the Pacific, Long Beach and OCSD), while not numerous in quantity or large in size, was invaluable. Sclerite size and shape were noted, along with calyx shape and confirmed polyp color. It would appear that M. californica has a wide range of polyp coloring (rarely white to commonly yellow or rich gold), while its sclerites are distinct in not having the large, densely warted, rounded spindles common to M. fruticosa (which only displays white polyps). In situ identification, therefore, can be challenging if the colony in question has white polyps; both M. californica (occasionally) and M. fruticosa (typically) have white polyps, while M. appressa (as M. plantaginea , included briefly below, for comparison) seems to always display yellow polyps, (which is normal for M. californica ). Despite the challenges regarding in situ identification, M. californica (as well as M. fruticosa and M. appressa (= M. plantaginea ) are all recognized as separate species in the WoRMS Database ( Cordeiro et al. 2018g).