Comprehensive DescriptionRead full entry
Solenosmilia variabilis Duncan, 1873
“The synonymy is complete for southern records only.
Solenosmilia variabilis Duncan, 1873, p. 328, pi. 42, figs. 11-18.—Moseley, 1881, p. 181, pi. 9, figs. 1-5.—von Marenzeller, 1904a, pp. 310, 311, pi. 15, figs. 4, 4a.—Hoffmeister 1933, p. 14, pi. 14, fig. 7.—Wells, 1958, p. 262.—Squires, 1969, pp. 16, 18, pi. 6, map 2.—Zibrowius, 1974a, pp. 768, 769; 1980, pp. 143-145, pi. 75, figs. A-N.—Cairns, 1979, pp. 136-138, pi. 26, figs. 2-4.” Cairns 1982, p. 31.
Description. “Colonies are bushy, achieved by intratentacular budding and its resultant dichotomous branching. Budding begins with an elongation of the calice and an increase in the number of septa. Next, the septa on opposite sides of the calice bridge over the fossa, dividing the calice in two but maintaining a connection between the polyps. Eventually the two corallites elongate and are completely partitioned by coenosteum. Normally, calices rarely exceed 5 mm in calicular diameter. The end branches may be quite slender (3-5 mm in diameter) or thick and massive (7-8 mm) and often anastomose. Basally the branches are very thick (up to 20 mm in diameter) and the colony is attached by an encrusting base also bearing corallites. The coenosteum is variable: it can be completely smooth and white; granular, glossy, and light gray; or granular with 8-10 ridged costae around the circumference of the branch. Septa are usually arranged in six systems and three complete cycles. S1 are highly exsert and have straight inner edges, which meet in the bottom of the fossa. S2 are about one-third the size of the Si and are much less exsert but considerably larger than the S3, which are developed only in the upper fossa. Sometimes, just before intratentacular division, a complete fourth cycle of septa is attained and some S5 may be present (e.g., 60 septa); however, the development of the S4 and S5 is very irregular. The inner edges of the S1-3 are straight and entire, whereas those of the S4 and S5 are dentate or laciniate. Septal granulation is low and very fine, producing a smooth texture. Tabular endothecal dissepiments are present. When the fossa is deep, a rudimentary columella is often present, composed of spongy, crispate trabeculae..” Cairns 1979, pp. 136-138.
“Discussion. Because of its distinctive branching pattern, S. variabilis is easily distinguished from the four other colonial genera that occur in Subantarctic waters: Madrepora, Enallopsammia, Bathelia, and Goniocorella. Both S. variabilis and M. oculata were collected at Eltanin station 1081 (east of the South Orkney Islands), which is the southernmost record for colonial Scleractinia. S. variabilis was taken in great quantity at Eltanin station 1346 (a seamount or ridge on the Heezen fracture zone of the Eltanin fracture zone system) in the South Pacific, indicating the possible presence of a deepwater coral bank. Other similar deepwater structures have been found in the North Atlantic and on the Campbell Plateau, south of New Zealand. The framework corals of the northeastern Atlantic banks are L. prolifera and Madrepora oculata (S. variabilis is present to a minor extent); those in the northeast Atlantic are Enallopsammia profunda and L. prolifera (again S. variabilis is present but not common); those on the Campbell Plateau are Goniocorella dumosa and pseudocolonial Desmophyllum cristagalli. The coral composition of the South Pacific bank is apparently about 98%, S. variabilis with a small amount of M. oculata. Other associated solitary corals are Desmophyllum cristagalli, Cyathoceras irregularis, and Caryophyllia sp. Other invertebrates found at the same station include Porifera, Hydroida, Stylasterina, Gorgonacea, Actiniaria, Nematoda, Bryozoa, Brachiopoda, Ophiuroidea, Asteroidea, Echinoidea, Holothuroidea, Pterobranchia, Polychaeta, Gastropoda, Polyplacophora, Bivalvia, Pycnogonida, and Crustacea. Without a sediment sample, seismic profile, and photographic documentation it is difficult to be conclusive, but in all likelihood a deepwater coral bank exists in this area.
Material. Eltanin sta. 254, USNM 47423; sta. 1081, USNM 47422; sta. 1344, USNM 47424; sta. 1345, USNM 47425; sta. 1346, USNM 47426; sta. 1403, USNM 47419; sta. 1414, USNM 47420; sta. 1416, USNM 47664; sta. 1422, USNM 47421; Specimens listed by Cairns (1979), USNM. Syntypes.
Types. The syntypes of S. variabilis, collected on the second cruise of the Porcupine, are deposited at the British Museum. Type-locality: off southwestern Spain; 1190-2003 m.
Distribution. Widespread in the Atlantic and Indian oceans. Circumpolar in southern seas: off South Africa; off Prince Edward Island; off lie Saint-Paul; off southeastern Australia; Hjort Seamount; Macquarie Ridge; off New Zealand; seamounts in South Pacific and Drake Passage; east of South Orkney Islands; off Tristan Island (Map 7). Not found off continental Antarctica. Squires's (1969) record off Chile is unsubstantiated. Worldwide depth range: 220-2165 m; Subantarctic records: 500-1830 m.” Cairns 1982, p. 31.