Goniocorella dumosa (Alcock 1902)

"Goniocorella dumosa (Alcock, 1902)

Pourtalosmilia dumosa Alcock, 1902, pp. 36, 37, pi. 5, figs. 33, 33a.

Goniocorella dumosa; Yabe and Eguchi, 1932, pp. 389, 390; 1936, p. 167; 1941b, pp. 162, 163; 1943, pp. 495, 496, figs. 1, 2.—Squires, 1960, pp. 197, 198, pi. 33, figs. 1-4; 1964a, p. 11; 1965b, pp. 785-787; 1969, p. 17, pi. 6, map 2. —Ralph and Squires, 1962, p. 11, pi. 4, fig. 1. —Squires and Keyes, 1967, p. 25, pi. 3, figs. 15, 16, text fig. 4.—Eguchi, 1968, C-43, pi. C-9, figs. 11, 12.—Podoff, 1976, pp. 27, 28, pi. 1, figs. 5, 6.

Description. Colony bushy, achieved by irregular extratentacular budding often at right angles to parent branch. Parent branch continuing to grow after budding; each budded branch elongating and also producing buds. Strength of colony reinforced by numerous slender (2 mm in diameter) extensions of coenosteum, these uniting adjacent branches, sometimes in scalariform arrangement [Squires, I960]. Branches cylindrical, often straight, 3-5 mm in diameter, each bearing round terminal calice. Colonies up to 1 m in diameter. Corallum light gray or white; polyps and tentacles orange. Coenosteum bearing low, rounded granules. Terminal corallites often with slightly ridged C1, and C2. Septa hexamerally arranged in three cycles. S1 very slightly exsert, with straight, vertical inner edges. Upper region of septa usually narrower than lower region; lower region almost reaching center of corallite. S2 and S3 progressively smaller; S3 rudimentary, with dentate inner edges. Septal faces usually smooth with fine granulation, but sometimes covered with tall, pointed granules. Fossa deep and vacuous. No columella or pali. Thin, tabular endothecal dissepiments occurring every 2-10 mm, giving dried corallum a light weight.

Remarks. On the basis of a specimen attached to an underwater cable, Squires [1960] calculated the growth rate to be at least 1.67-2.94 mm/year in height. Squires [1965b] also suggested that G. dumosa is the primary sediment-forming coral of a deepwater coral bank (coppice) on the Campbell Plateau, off New Zealand. Two other locations of Goniocorella-Desmophy1lum coppices are given by Squires [1965b].

Discussion. Goniocorella is monotypic and distinguished from other southern colonial corals by its distinctive branching pattern, coenosteal extensions, and lack of columella.

Material. Eltanin sta. 1816, USNM 47509; sta. 1848, USNM 47667. NZOI sta. A-706, USNM 47511; sta. B-319, USNM 47506; sta. C-410, USNM 47510; sta. C-618, USNM 47507; sta. C-633, USNM 47508; sta. D-145, USNM 53382; sta. D-175, USNM 47505. Some of these records first reported by Ralph and Squires [1960], Squires [1965b], and Squires and Keyes [1967].

Types. The syntypes of G. dumosa are at the Indian Museum (Calcutta). Type-locality: Banda Sea; 469-487 m.

Distribution. Off Japan; Banda Sea; off Norfolk Island; off Bounty Islands; off New Zealand; Chatham Rise; Campbell Plateau (Map 7). Depth range: 100-638 m." Cairns 1982, Plate 9, figs. 7-9; Plate 10, figs. 1, 2

Goniocorella dumosa (Alcock, 1902)

Pourtalosmilia dumosa Alcock, 1902c:36–37, pl. 5: fig. 33.

Goniocorella dumosa.—Yabe and Eguchi, 1932a:389–390; 1936:167: 1943:494–496, figs. 1, 2; 1942b:162, 163.—Eguchi, 1965:291, 2 figs.: 1968:C43, pl. C9: figs. 11, 12.—Cairns, 1982:31–34, pl. 9: figs. 7–9; pl. 10: figs. 1, 2 [synonymy].—Cairns and Keller, 1993:250, fig. 6E.—Song, 1991:134–135. pl. 1: fig. 3; pl. 2: figs. 4–7.

Goniocorella sp. aff. G. dumosa.—Eguchi and Miyawaki, 1975:58.

DESCRIPTION.—Colony bushy, budding often at right angle to parent branch. Colony reinforced by slender (about 2 mm in diameter), hollow, tubular coenosteal bridges, which unite adjacent branches. Branches cylindrical, 3–5 mm in diameter, each bearing a terminal calice of equal diameter. Costae inconspicuous. Corallum white or light brown.

Septa hexamerally arranged in 3 complete cycles according to the formula: S1>>S2>S3. S1 not very exsert and quite narrow (only about 0.6 mm wide), with straight, vertical inner edges that extend to uppermost dissepiment. S2 much thinner (only about 0.2 mm wide); S3 smaller still (only about 0.1 mm wide), both S2 and S3 extend deep into fossa. Fossa usually deep and vacuous, bordered laterally by inner edges of narrow septa and basally by a horizontal dissepiment. Thin, tabular endothecal dissepiments occur every 2–10 mm, giving the corallum a very low density.

azooxanthellate

88-1488 m

Known from seamounts and knolls