Dermatobranchus cymatilis Gosliner & Fahey, 2011

Description

Body broad, flattened, narrowing posteriorly. The dorsum bears a series of longitudinal ridges. The oral veil extends forward with blunt corners. Widely spaced rhinophores sit behind the oral veil with longitudinal lamellae on the rounded club; the stalk does not narrow noticeably.
Ground colour of the dorsum and foot is opaque white, with a deep blue foot margin. A pinkish-orange patch lies about midway across the dorsum. Dark rays of pigment extend perpendicularly from the mantle edge both downward onto the foot margin and upward into dark patches along the mantle, with the dark patches forming broken irregular bands across the dorsum. The dorsal ridges bear darker crests. Rhinophore stalks are white and the clubs are dark. The oral veil is opaque white with dark perpendicular rays and an orange margin near the dark patch on its posterior side.

Distribution

Known only from Okinawa, Japan (type locality: Horseshoe Cliffs, west-northwest of Onna Village, 60 m).

Etymology

Verbatim from the original description (Gosliner & Fahey, 2011, p.298):

The specific name cymatilis is from the Latin adjective meaning 'sea-coloured or blue' to describe the deep blue foot margin on this species.

Remarks

The dark rays on the dorsum and the blue foot margin separate it from related species such as D. striatus, D. dendronephthyphagus and D. semistriatus.

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References

• Dermatobranchus sp. 10, Gosliner T.M., Behrens D.W. & Valdés Á. (2008). Indo-Pacific Nudibranchs and Sea Slugs: A field guide to the world's most diverse fauna. Sea Challengers Natural History Books, 426 pp.
• Dermatobranchus cymatilis sp. nov., GOSLINER T.M. & FAHEY S.J. (2011). Previously undocumented diversity and abundance of cryptic species: a phylogenetic analysis of Indo-Pacific Arminidae Rafinesque, 1814 (Mollusca: Nudibranchia) with descriptions of 20 new species of Dermatobranchus. Zoological Journal of the Linnean Society. 161(2): 245-356. https://doi.org/10.1111/j.1096-3642.2010.00649.x
• ウミイロオトメウミウシ（新称）, 中野理枝. (2018). 日本のウミウシ. 文一総合出版.