Melithaea oyeni, 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 : 27-28

Taxon classification Animalia Alcyonacea Melithaeidae

Melithaea oyeni sp. n. Figures 66d, 70, 71, 74

Material examined.

Holotype RMNH Coel. 41927 (AKM 408), Watari-se bank, off Izu Isls., 34°02.8620'N, 138°54.8090'E - 34°02.9190'N, 138°54.6810'E, 101.1-106.2 m, R/V Tansei-maru, KT04-06 cruise, St.WS-2, 1m ORI Dredge, coll. A.K. Matsumoto, 30 April 2004; paratype RMNH Coel. 41928 (AKM 1606), Takase West, Izu Ridge, 34°26.5'N, 139°07.2'E, 104-127 m, R/V Tansei-maru, KT87-19, St. TW1, coll. S. Ohta, 8 December 1987.

Description.

The holotype is a 8 cm long fragment with holdfast (Fig. 66d). At the base the stem is 3 mm wide, the end branches are only 1 mm wide. The polyps are situated bilaterally on the branches, the calyces are dome-shaped, and most polyps are expanded. Points with slightly bent spindles up to 0.20 mm long, distal end with leaves (Fig. 70a). Collaret with bent spindles up to 0.30 mm long, middle part with more developed tubercles (Fig. 70b). Tentacles with platelets, the larger ones crescent-shaped with irregular projections (Fig. 70c). These platelets are up to 0.15 mm long. Pharynx with straight spiny rods, up to 0.05 mm long (Fig. 70d). Coenenchyme with predominantly capstans, double disks (Fig. 70f) and disk spindles (Figs 70g, 71c), 0.05-0.15 mm long, and small clubs (Fig. 71a), up to 0.10 mm long. Spindles are also present, 0.10-0.25 mm long, with simple tubercles (Fig. 71d). The calyces with additional clubs, up to 0.15 mm long (Fig. 71b).

Color.

Colony orange with yellow polyps, coenenchymal sclerites orange, polyp ones yellow.

Variation.

RMNH Coel. 41928 has similar sclerites and color.

Distribution.

Off the Izu Islands (Fig. 74)

Etymology.

The species is named after Mr. T.J.G.M. van Oyen (NBC) in appreciation of the many microscope slides he prepared for the second author.

Remarks.

The species mostly resembles Melithaea abyssicola but has overall somewhat larger sclerites, a difference difficult to notice when not having both species at hand. However, the double disks of Melithaea oyeni sp. n. are strikingly different, much wider than those of Melithaea abyssicola (compare Fig. 70f with Fig. 3b).