Dermatobranchus albopunctulatus Baba, 1976

アワシマオトメウミウシ Dermatobranchus albopunctulatus

Location: Futou beach, Tago, Futou, Dougashima, Shizuoka, Japan
Date: 2013/06/10
Length: ??mm
Depth: 3.0m
Water temperature: ??℃

Description

A small to medium-sized Arminidae, body length 10-60 mm. The mantle appears smooth to the naked eye but bears 30-35 fine longitudinal ridges visible under a lens. Ground colour above and below yellowish white, sometimes with dark shading on the median back, sole, and sides. The longitudinal ridges themselves are yellowish white. Diagnostic feature: the grooves between the ridges are densely covered with opaque white fine dots, and similar dots occur on the upper surface of the head veil. Rhinophores bluish black above, white below. The head veil, mantle, and foot are each bordered by a narrow orange line. The jaw plate has no masticatory process (subgenus Pleuroleura).

Distribution

Type locality: Uchiura coast near Awashima, Suruga Bay, Japan. Type-series localities also at Tomioka, Amakusa. The species occurs along the Pacific coast of central and southern Japan in association with gorgonian (octocoral) colonies at 15-30 m depth.

Etymology

The specific epithet albopunctulatus is a Latin compound of albus ("white") and punctulatus ("finely dotted"), meaning "finely white-dotted", in reference to the opaque white dots in the grooves and on the head veil.

Remarks

Originally described in the subgenus Pleuroleura, as Dermatobranchus (Pleuroleura) albopunctulatus. Most closely related to Dermatobranchus sagamianus in the strikingly projecting median cusp of the central tooth, but distinguished by the combination of very numerous fine longitudinal ridges and opaque white dots in the grooves between ridges and on the head veil.