Calcigorgia gigantea Matsumoto & Van Ofwegen & Bayer 2019, sp. n.

Calcigorgia gigantea sp. n.

Figures 1a, 2 c–d, 4–5

http://zoobank.org/ 7050EC0C-7AE5-439C-AE76-3997997ABEFC

Material examined. Holotype, USNM 1013069, Tanaga Pass west of Tanaga Island, Andreanof Islands, Aleutian Islands, Bering Sea, 51°N 137.64'N 178°19.2'W, depth 375 m, bottom temp. 4 °C, F/ V Pacific Knight, cruise 94-1, haul 121, 5 July, 1994 (Figure 2c); paratypes USNM 1004615 Amchitka Pass, Rat Islands, Aleutian Islands, 51.2885°N 178.947°E, depth 347–391 m, field number AB01-65, coll. McCluskey, P. (Figure 2d); USNM 1010177, Semisopochnoi Island, Rat Islands, Aleutian Islands, West Bering Sea, 52.1756°N 179.608°E, depth 128–135 m, R/ V Dominator, st. 135, 24 June 2000.

Description. The holotype is 7 cm wide and 10 cm high (Figure 2c). The stem is 2 cm long and about 6 mm wide. The polyps are about 9–10 mm high and 5–6 mm wide. Tentacles without sclerites. Polyps with poorly developed clubs (Figure 4a), up to 0.60 mm long and spindles up to 0.90 mm long (Figure 4 b–c); all with simple tubercles. The coenenchyme with smaller spindles, 0.20–0.50 mm long, with more developed tubercles (Figure 4c).

Etymology. From the Latin gigantea, giant or very large, referring to the large polyps and sclerites

Colour. The preserved holotype is white, all sclerites are colorless.

Distribution. Aleutian Islands, both East and West Bering Sea in 128–391 m (Figure 1a).

Remarks. The colony of USNM1004615 is rather slender and has smaller polyps than the holotype (Figure 2d) but its polyp sclerites (Figure 5 a–b) are very much like those of the holotype. The coenenchyme has smaller spindles, up to 0.20 mm long, and some capstans (Figure 5c). Calcigorgia gigantea sp. n. is unique in the genus by its large polyps and sclerites.