Muricea fruticosa Verrill, 1868

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 fruticosa Verrill, 1868 Figures 43A, B, 44A, B, 45 A–D, 46, 47A, B, 48 A–E

Muricea fruticosa Verrill, 1868a; 1869a: 428-430; pl 7, fig. 2. Kükenthal 1919: 752; 1924: 142-143. Hardee and Wicksten 1996: 129-130. Breedy and Guzmán 2016b: 9-14.

Muricea fruticosa var. typica Verrill, 1868a; 1869a: 428-430. Kükenthal 1924: 142.

Muricea fruticosa var. miser Verrill, 1869a: 430. Kükenthal 1919: 752; 1924: 143.

Thesea crosslandi Hickson, 1928: 354-356 (syn. nov.).

Pseudothesea crosslandi (Hickson, 1928). Stiasny 1943: 64-66 (syn. nov.)

Type locality.

(Lectotype) Panama, Pearl Islands, 11-14 m.

Type specimens.

Lectotype YPM 1574C [dry]; additionally, YPM 1660 [wet], YPM 1792 (fragment from Lectotype) [dry], and YPM 3067C [dry], are all listed as Syntypes. There are several specimens listed as Syntypes at NMNH: for instance, USNM 52292 [dry], with SEM images from stub #239. Syntype material at NMNH was examined.

Material examined.

~14 lots (see Appendix 1: List of material examined).

Description.

Colony (Figures 43A, 46) fairly large; dense, abundant branching; not reticulate. Branching irregularly dichotomous (also seen as cespitose/fruticose, tightly bush-shaped variant, with rather small, somewhat clavate branchlets outside California Bight; variant description not discussed here). Prominent, spreading, spinose calyces create rough texture to branches of colony. Colony (of Figure 46) very bushy; not in one plane. Colony stands up to three feet (90 cm) tall (Figure 43A), but usually shorter (30 cm). Main stem stout, short, arising from large, irregular base, usually dividing at once into several large, thick, unequal main branches, rapidly dividing and subdividing in irregular manner; branching extensive, such that main branches soon lost among crowded, crooked secondary branches. Branches and branchlets usually not more than 7.0-12 mm apart; branching can be in one plane, but not always. Small branches near ends often divide in irregular dichotomous manner, sometimes coalesce; very numerous, nearly equal in size, usually distinctly curved and crooked, spreading out at origin with a broad curve. Terminal branchlets short, 7.0-40 mm long, 2.0-3.0 mm thick, often curved, not tapering, either ending evenly or clavately, with obtusely rounded ends. In overall appearance, can look much like the colony shape of M. californica (perhaps reflective of similar environmental conditions). Color of living colony generally brown (darker) with white polyps; mostly deep reddish orange, rusty-brown; branchlet tips and calyces deep reddish brown, color generally fading to yellowish brown in proximal portion of branchlets, fading into light yellow, tinged with brown in main branches and trunk. Dry specimens orange-rusty brown, while polyps are pure white, situated on upper side of calyces; near distal end, aperture filled with yellow polyp sclerites, arising from bases of tentacles. Horn-like axis yellowish wood-brown at base and in larger branches ( Hardee and Wicksten 1996 stated axis dark brown at base); darker reddish brown, translucent in smaller branches; light amber-yellow, translucent, slender up into branchlet tips. Calyces close together, but not overlapping, spreading outward and upward, 45 degrees from branch when closed, nearly 90 degrees with polyp extended; prominent, with conspicuous shelves opening distally, conical to columnar, larger and closer (1.0 mm) toward tips (Figure 43B), approximately as high (1.0-2.0 mm) as they are broad (1.0-1.5 mm); on larger branches low, rounded, without prolonged lower lip, better developed than at base where they are flatter, small and spread apart (2.0 mm). Those better developed have an obvious lower lip, sharp and long with very large, long, stout sclerites as spindles (some of which approximately as long as the calyces) which lie parallel to each other, projecting past upper margin of lower lip, giving colony a prickly feel when touched; upper lip small or barely noticeable. As calyces do not overlap, outer, thin coenenchyme easily seen lying between calyces, characterized by extremely large, stout, sclerites, visible to naked eye, and curving around them, often larger than calyces; these sclerites may be missing near base of colony or in poorly preserved specimens. Sclerites (Figure 44A, B) vary in color from brownish yellow and yellowish white to deep reddish brown. Largest sclerites (of outer coenenchyme), reddish orange-brown in color, up to 3.0 mm long; several shapes visible (Figures 44A, B, 45, 47A, B, 48 A–E). One shape, very distinct, mostly stout, blunt and truncate, almost rectangular; longer, large, massive ones rather thick in middle, tapering somewhat abruptly at ends, densely, evenly covered by small tubercles (Verrill 1868 stated longer ones covered by small, sharp spinules on one side; other parts covered with crowded rough warts; these I refer to as tardigrade-like sclerites; Figures 44A, B, 45D, 47B, 48E). Second largest form irregularly fusiform, covered with tubercles; third form (Figure 48D) hook-shaped either on one end, both ends curving inward, or one end forked, the other tapering to a point; the latter often covered on ends with small, sparse, occasionally spiny tubercles, becoming more densely covered with tubercles toward the center, usually found around base of calyces. Medium-sized sclerites (~1.0 mm) more regular, fat (stout) in middle usually tapering to acute points; one side or one end covered with quite large, very sharp, simple projections, other side with densely crowded, rough microtuberculate warts. Sclerites of inner coenenchyme distinctly smaller, color ranging from yellow to white, fusiform, slender, often tapering to sharp point, covered with distinctly raised tubercles or warts (Figure 48B). Calyx sclerites long, up to 1.6 mm, very irregular and oddly shaped, mostly fusiform, one end often forking slightly or very noticeably, evenly covered with distinct tubercles, with some unilaterally spinose projections.

Generally, sclerites shown in Hardee and Wicksten (1996) appear to have extremely dense coverings of warts and bumps, the latter smallish in size. As well, they seem to cover a greater portion of the surface area of the sclerite as compared to those seen in drawings for sclerites of M. californica . Examinations of sclerites, for specimens identified as this species, reveal that sclerites can have flame-like teeth, these running almost the full length of the sclerite, on a side (what are termed nudibranch sclerites (Figure 45A), as those of Matamoros-Rosales (1984), rather than at an end such as seen in a torch. Very largest sclerites (tardigrade-like) rounded, densely warted, with projections coming off one of the longer sides, creating the appearance of legs and claws (like those of a tardigrade; Figures 44, 45D, some in Fig. 48E). Generally, sclerites have very dense tubercle coverings. The largest sclerites in this species are decidedly larger than those of M. californica ; this will be the case despite what might have been concluded from having only looked at polyp color. This agrees with data provided in both Harden (1969) and Grigg (1970).

The colony shown in Figure 46 displays a few odd features, warranting further mention. Branching primarily pinnate to dichotomous. Colony measures ~7.5 cm tall, 4.0 cm wide. Slightly central main stem runs entire height of colony, with some slight curving laterally in random sections of stem; multiple branches all begin directly above or from base, many coming off of main stem. Branches often angle out a very short distance then curve upwards. Primary branches average 3.0-4.0 mm long, diameter ~1.0-2.0 mm (excluding calyces); diameter appears consistent from axillary branch points to branch tips. Calyces very columnar (1.0-2.0 mm wide, ~3.0 mm tall), heavily covered with longitudinally-oriented sclerites; polyps, many partially to fully extended from calyces, cream or light yellow; appear smooth. Calyces on all sides of branches, in some areas of colony very dense, in other areas calyces with some little distance between themselves, where sclerites can be seen on coenenchyme surface, lying sometimes longitudinally with the branches, sometimes not; latter more transverse (or oriented slightly in a triangular pattern) at base of calyces; calyces cover entire colony, right down onto coenenchymal surface of colony’s base. Calyces generally appear distinct reddish brown due to large, conspicuous sclerites. Color of colony generally darker distally, reddish brown, grading from free branch tips of colony to much lighter yellow or cream proximally, in stem and base (due to light-colored sclerites, usually small in size); polyps appear very light yellow, cream to white. Majority of calyx-bearing polyps appear such that they give colony an overall swollen appearance (as though branches of colony are covered with small, round grapes). This is the most unique feature of this colony; this may reflect an active reproductive state at the time of collection; specimen’s reproductive condition is still a question. Some calyces, scattered on all branches, tend to curve upwards slightly. The sclerites shown in both light microscopy (Figure 47A, B) and SEM (Figure 48 A–E) in some ways match those for the colony of Figures 43-45, and yet in other ways do not clearly point to it being the same species. Based on this single specimen in the SBMNH collection (SBMNH 265945), from Long Beach, California, it requires further study. The biology of this colony, and its swollen appearance, has not been further explored or explained to date, other than to indicate that specimen was collected from very far into the back channels of Long Beach Harbor, quite a distance from open water (D Cadien, LACSD, pers. comm.).

Etymology.

Latin, fruticosu- meaning shrubby (bush-like); Verrill gave no specifics as to the derivation of the species name.

Common name.

Brown gorgonian; Fruitful purple one; Bushy rust gorgonian; Robust gorgonian (as indicated in various field/diving guides).

Distribution.

Potentially from Panama, up along California coast, perhaps as far north as Los Angeles County, California, with maximum, though infrequent, northern limit Point Conception, California. In a list of California sites, showing depth ranges, the following are indicated: Mainland: Point Loma: 5-14 m; La Jolla: 3-12 m; (USNM 50192 was collected at 11 m at La Jolla, in the Torrey Pines kelp bed, 5 miles north of Scripps Institution); Newport Beach: 0-12 m; San Pedro: 0-15 m; Santa Barbara: 5-8 m; Naples Reef: 5-11 m; Islands: Coronados Islands: 2-12 m; San Clemente Island: 21 m; Santa Catalina Island: 5-18 m.

Biology.

Seen more commonly in southern areas of California kelp beds (Ricketts, 4th Ed. 1968); also, offshore pilings. Seen as well in lowest intertidal zone, outer Los Angeles Harbor; one of the most common species in southern California, in 15-30 m depths, Point Conception to Baja California ( Grigg 1977; Gotshall 1994, 2005). Both this and M. californica seem to prefer subtidally occurring solid substrata at depths between 1.0-30 m ( Grigg 1977). Lissner and Dorsey (1986) reported that while this species is common around the California Channel Islands and rocky areas of the mainland, it is conspicuously absent on the Tanner and Cortes Banks and the Santa Rosa - Cortes Ridge. Grigg (anecdotal communication) reported that populations of Muricea may be limited by cold water and/or poor dispersal abilities of the larvae. Grigg (1974) stated that this species is ca. one-tenth as abundant as M. californica off La Jolla. Based on work done by Grigg, it was estimated that a colony 30 cm high is ~20 years old. As very few colonies are seen larger than that, few colonies likely exceed this age. Mortality attributed mostly to abrasion, occurring when particulate matter is suspended in the water during periods of high waves and by smothering coming from accumulations of sand. One untitled and unpublished identification guide stated that colonies are able to survive in some of the most polluted near shore waters, as well as uncontaminated offshore waters. It appears this species is immune to encrustations known to cause mortality in M. californica . (SBMNH 422390, collected by MacGinitie in Newport Bay, if indeed this species–original identification indicated it was, based on white polyps, but sclerites do not support the identification–does have several galls produced by an acorn-type barnacle, on bare axis as well as on an area covered by coenenchyme.) Apparently fed upon by only one species of fish, the Garibaldi Hypsypops rubicunda . Grigg (1974) calculated that between 10% and 15% of annual growth of this species and M. californica is cropped by Garibaldi predation.

Remarks.

Gift of FH Bradley; collected below low, low-water mark. Panama and (?) Pearl Islands, 6-8 fm (11-15 m) ( Verrill 1869a). Identified as Muricea fruticosa var. typica (?).

There are two specimens at NMNH identified as this species, with SEM images: USNM 57171, SEM 237-238 (label reads ‘Albatross’ 28-29) and also, " Muricea fruticosa Verrill," collected by Limbaugh, from St. (Cape) Lucas Canyon, SEM image 999. NMNH has an additional lot (USNM 52486), collected at Point Vicente, California, along with material in the “Limbaugh” Collection, which could well be this species, having been collected from the following locations (multiple lots): from California, at Huntington Beach Gas & Electric Steam Plant discharge pipe; from Baja, at Turtle Bay.

For all colonies of Muricea found in the California Bight, there is the possibility of other species in the genus not previously reported as appearing in the Bight, which may have very similar shape, etc. to the commonly recognized species described here. Perhaps there are new, undescribed species. It may well be that previously described species other than the standards make appearances in the Bight, and do so more often than previously thought. This possibility is supported by the fact that climatic factors can greatly expand ranges, even if only temporarily. A number of Mexican species may occasionally (or more often) make an appearance in the California Bight during certain substantial climatic/atmospheric events, such as an El Niño.

This conclusion has some support; Hardee and Wicksten (1996) in their closing paragraphs state "(a)lthough our material could be identified as (simply) M. fruticosa and M. californica , it is possible that other species of Muricea occur in southern California." They recommended that a comparison of a series of specimens be made. This would help to clarify which previously described species are valid and which are "merely growth forms." I agree with that recommendation. Fresh Muricea colonies, collected in a very intentional manner, from south to north, both within the Bight and to the south outside the Bight, must be done; that collection process is underway, with the help of the Santa Barbara Museum of Natural History’s Sea Center staff, staff of the Aquarium of the Pacific in Long Beach, California and staff of both the Los Angeles (LACSD) and Orange County (OCSD) Sanitation Districts. With the dramatic weather events we have recently experienced here in California, it will be interesting to see whether other species of the genus are making an appearance, for any length of time.