Melithaea undulata ( Kuekenthal , 1908)

Matsumoto, Asako K. & van Ofwegen, Leen P., 2015, Melithaeidae of Japan (Octocorallia, Alcyonacea) re-examined with descriptions of 11 new species, ZooKeys 522, pp. 1-127 : 37-40

Taxon classification Animalia Alcyonacea Melithaeidae

Melithaea undulata ( Kuekenthal, 1908) Figures 87 d–e, 94, 95, 96, 97, 98

Acabaria undulata Kükenthal 1908: 196; 1909: 63, figs 68-69, pl. 5 fig. 28, pl. 7 figs 40-43 (Japan); 1919: 179; 1924: 76; Hickson 1937: 181.

? Acabaria undulata ; Rho et al. 1980: 54 (Korea Strait); Song 2000: 121 (Korea Strait).

Material examined.

Holotype ZMB 5803, Sagami Bay, Japan, 700 m, coll. Doflein, 1904/05; previously unidentified museum material: ZMUC ANT-000592, Sagami Sea, Japan, 500 fms (715-914 m), coll. Dr. Th. Mortensen, 25 June 1914; BMNH 1921.10.26.9-1, BMNH 1921.10.26.9-2, Misaki, Sagami Bay, 200 fms (286-366 m), coll. A.V. Insole, May 1921; MZS-Cni57, Sagami Bay, 200 m, coll. Doederlein. UMUTZ-CnidG-14, Niijima Is., Izu Isls., coll. sp. no. 80, 22 April; UMUTZ-CnidG-20, Dokesuba, Sagami Bay, 130 hiro (186-196 m), coll. Kuma Aoki, 9 August 1897; UMUTZ-CnidG-234, Mochiyama, Sagami Bay, 400 hiro (572-604 m), possibly coll. Kuma Aoki; AKM 502, Ose-zaki, Suruga Bay, 137-155 m, coll. K. Kitazawa, 22 July, 2004; RMNH Coel. 42030 (AKM 724), off Tanega-shima Is., East China Sea, 30°24.62'N, 131°08.46'E - 30°24.95'N, 131°08.32'E, 468-502 m, R/V Tansei-maru, KT07-1, st. TN-3, 1 m biological dredge, coll. A.K. Matsumoto, 23 February 2007; AKM 1034, Koshiki Knoll, off Kagoshima, East China Sea, 31°36'N, 129°19'E, 497-535 m, R/V Tansei-maru, KT08-3, st. KS-01, coll. A.K. Matsumoto, 6 March, 2008; AKM 1591, Danzyo-Basin, East China Sea, 31°58.02'N, 129°02.28'E - 31°59.30'N, 129°01.19'E, 711-801 m, R/V Tansei-maru, KT00-17, St. DZ-1, ORE Beam Trawl of 3 m span, coll. Suguru Ohta, 12 December 2000; AKM 1592, same data as AKM1591; AKM 1593, South East off Taito-saki Cape, Boso Peninsula, 35°05.086'N, 140°51.718'E - 35°04.176'N, 140°50.92'E, 975-1027 m, R/V Tansei-maru, KT03-17, st. TS6-3, coll. S. Ohta, 17 November 2003; AKM 1599, South off Daio-zaki Cape, Kumano-nada, 34°05'N, 136°51'E, R/V Tanisei-maru, KT94-07, st. KN 25, 25 May 1994, 475-494 m, coll. S. Ohta; AKM 1604, west off Izu-Oshima, Sagami Bay, 139°15.0'E 34°40.4'N, 415-440 m, R/V Hakuho-maru, KH-78-05, st. BS8, 2 m S.-A. beam trawl (on label), 7 December 1978.

Re-description.

Colony branched in two parallel planes. Points with slightly bent spindles up to 0.25 mm long, distal end with more developed tubercles (Fig. 94a). Collaret with bent spindles up to 0.30 mm long, middle part with more developed tu bercles (Fig. 94b). Tentacles with platelets, the larger ones crescent-shaped (Fig. 94c). These platelets are up to 0.15 mm long. Pharynx with straight spiny rods, up to 0.05 mm long (Fig. 94d). Coenenchyme with capstans (Fig. 95b) about 0.05 mm long, several slightly unilaterally spinose, small clubs of the same length (Fig. 95a); spindles 0.10-0.30 mm long (Fig. 95c); all with simple tubercles. The calyces with additional clubs, up to 0.12 mm long (hardly present in type material). The axis has smooth and sparsely tuberculate rods (Fig. 94e).

Color.

Colony red, tentacle sclerites colorless, all others pink.

Variation.

AKM 502 is yellow with yellow sclerites.

Distribution.

Southern Pacific coast of Japan, north to Sagami Bay, south to East China Sea; Suruga Bay, off Taito-Saki Cape, Boso Peninsula; off Tanega-shima Is., Koshiki Knoll., Danzyo Basin, off Kagoshima (Fig. 98).

Remarks.

The type specimen clearly has damaged sclerites, probably caused by formalin. Recently collected material shows less rounded sclerites (Figs 87e, 96, 97). Double disks are present but so poorly developed that they can hardly be recognized as such.

The species resembles Melithaea tenuis but differs in having longer spindles (up to 0.30 mm long versus up to 0.18 mm long in Melithaea tenuis ), and lacking unilaterally spinose spheroids. It also resembles Melithaea corymbosa , but that species has mostly more slender, shorter spindles. Moreover, Melithaea undulata has poorly developed tentacle sclerites compared with the other two species.

Apparently the type material is mostly lost, only a small fragment remained (Fig. 87d) of a colony described as being 21 cm long ( Kükenthal 1909).