Melithaea ryukyuensis, Matsumoto, Asako K. & van Ofwegen, Leen P., 2015

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: 28-29

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Melithaea ryukyuensis

sp. n.

Taxon classification Animalia Alcyonacea Melithaeidae

Melithaea ryukyuensis   sp. n. Figures 66e, 72, 73, 74

Melithaea   sp. A: Aguilar-Hurtado et al. 2012: 62, fig. 5 (Okinawa).

Material examined.

Holotype UMUTZ-CnidG-32, Nakagusuku Bay, Okinawa Prefecture, Japan, diving, 16 April 1901; paratypes, UMUTZ-CnidG-254, same data as holotype; UMZC I.36300, S.W. Japan. T. Mizobuchi (purchased). Reg. Jan. 31.1903, 16.


The holotype is a 14.5 cm long fragment without holdfast (Fig. 66e). At the base the stem is 15 mm wide, the end branches are only 1 mm wide. The polyps are situated on one side of the colony, the calyces hardly project beyond the coenenchyme, and most polyps are retracted. Points with slightly bent spindles up to 0.10 mm long, distal end with more developed tubercles (Fig. 72a). Collaret with bent spindles up to 0.15 mm long, middle part with more developed tubercles (Fig. 72b). Tentacles with platelets, the larger ones crescent-shaped with irregular projections (Fig. 72c). These platelets are up to 0.10 mm long. Pharynx with straight spiny rods, up to 0.05 mm long (Fig. 72d). Coenenchyme with predominantly capstans (Fig. 73a, d), double disks (Fig. 73b) and disk spindles (Fig. 73c), 0.05-0.10 mm long, and small clubs with rounded heads, 0.05 mm long (Fig. 72f). Spindles are also present, 0.10-0.20 mm long, with complex tubercles (Fig. 73e). The calyces with additional clubs, up to 0.14 mm long (Fig. 72g). The axis has smooth and sparsely tuberculate rods (Fig. 72e).


Colony orange with yellow polyps. Part of calyx sclerites and all polyp sclerites yellow, all others orange.


Okinawa, Japan (Fig. 74).


The material of UMUTZ-CnidG-32 was probably collected during the Ryukyu (= Okinawa) expedition by K. Mitsukuri and I. Ikeda, in April, 1901. UMZC I.36300 is dried material. According to us this is Melithaea   sp. A of Aquilar-Hurtado et al. (2012) as the sclerite images given by them resemble ours. Melithaea ryukyuensis   mostly resembles Melithaea abyssicola   , which has overall larger sclerites but much smaller spindles in the coenenchyme.