Bebryce rotunda, Matsumoto, Asako K. & van Ofwegen, Leen P., 2016

Matsumoto, Asako K. & van Ofwegen, Leen P., 2016, The genus Bebryce (Cnidaria, Octocorallia, Plexauridae) at Japan, with descriptions of three new species, ZooKeys 587, pp. 1-20 : 4-6

Taxon classification Animalia Alcyonacea Plexauridae

Bebryce rotunda sp. n. Figures 1, 2d, 7, 8

Material examined.

Holotype RMNH Coel. 42076 (AKM 881), Hachijo I., Izu Is., Japan, 33°20.9082'N, 139°41.1841'E - 33°21.0775'N, 139°40.4931'E, depth range 185-213 m, RV Tansei-maru, KT07-31 cruise (Kuramochi leg), st. 14 (L-7-200), chain bag dredge, coll. A.K. Matsumoto, 26 November 2007.

Description.

The holotype RMNH Coel. 42076 (AKM 881) is a sparsely branched colony 10 cm long (Figure 2d). The calyces are placed spirally all around the slender branches, which are about 1 mm wide. The stem is 2 cm wide. The dome-shaped calyces are about 2 mm wide and high.

The anthocodiae are armed with a crown and points consisting of a transverse crown with curved spindles up to 0.35 mm long (Figure 7a) and eight points formed by spindles 0.35 mm long (Figure 7b) placed in a chevron-like pattern beneath the tentacles. These spindles have simple tubercles and a distal spiny end. The tentacles contain flattened, dragon wing sclerites up to 0.2 mm long (Figure 7c).

The sclerites of the outer surface of coenenchyme and calyces are rosettes consisting of a cup-shaped thorny projection arising from a warty base. These rosettes are 0.10 mm tall, have a flared calyx part about 0.10 mm in greatest diameter with blunt processes (Figure 7d) or the rim of the cups is formed several strong, laciniated projections (Figure 8b). Toward the calycular apertures the rosettes become asymmetrical (Figure 7e), with the margin of the calyx becoming much elongated forming a blade-like process that projects from the surface and surrounds the calycular aperture. These sclerites are up to 0.15 mm long.

The plates of the inner coenenchyme are tuberculate disks up to about 0.15 mm in diameter with tuberculate rim and central process on one surface (Figure 8a).

Colour. The holotype is creme.

Etymology.

From the Latin rotundus, wheel-shaped, round, referring to the round disks of the coenenchyme.

Comparisons.

Bayer and Ofwegen (2016) mentioned only two species with tuberculate disks and cup-shaped rosettes, Bebryce species A and Bebryce thomsoni Nutting, 1910. The present species differs from these two by having disks with a smooth central part and a small process in the middle, while those of Bebryce species A and Bebryce thomsoni have tubercles all over the disk.