Chromodoris willani Rudman, 1982
- Location
- Mini Dream Hole, Okinawa Island (Onna and Yomitan area), Okinawa, Japan
- Date
- 2015/10/19
- Length
- 30mm
- Depth
- 15.0m
- Water temperature
- 24.0℃
Description
Mantle ground colour pale blue with a thin white edge band; the boundary between the white and blue regions is diffuse. A thin black line outlines the mantle outside the rhinophores and gills, set in from the edge; another thin black median line runs from between the rhinophores to the gill pocket (broken centrally in most specimens). Gills and rhinophores are translucent brown with white spots and patches. Sides of the body and foot are pale blue with a white border, sometimes with three black lateral lines. The mantle is elongately ovate with overlap; up to eight simple gills stand vertically in a posteriorly-open horseshoe. Largest specimen 22 mm preserved (holotype 14 mm).Distribution
Type locality is the north-east side of the Pango Peninsula, Mele Bay, Efate Island, Vanuatu (18 m depth, July 1976). Originally recorded only from Vanuatu (Pango Peninsula, and the wreck of the President Coolidge off Espiritu Santo at 30 m); subsequent records extend to Indonesia, the Philippines, Malaysia, Guam, and Japan.Etymology
The specific epithet willani honours Dr R. C. Willan of the University of Queensland, who collected the type material and provided other valuable chromodorid specimens to the author (verbatim from the original description).Remarks
Extremely similar to Chromodoris lochi and Chromodoris boucheti but is distinguished by (1) an elongately ovate (not spatulate) mantle, (2) translucent brown gills and rhinophores with white patches (versus orange-yellow in Chromodoris lochi), and (3) a much larger central radular tooth.References
- ミゾレウミウシ, 益田一. (1999). 海洋生物ガイドブック. 東海大学出版会.
- ミゾレウミウシ, 益田一. (1999). 海洋生物ガイドブック. 第2刷. 東海大学出版会.
- クロモドリス・ウィラニ, 小野篤司. (1999). ウミウシガイドブック. TBSブリタニカ.
- ミゾレウミウシ, 小野篤司. (2000). ウミウシガイドブック. 第2版. TBSブリタニカ.
- クロモドリス・ウィラニ, 殿塚孝昌. (2003). ウミウシガイドブック〈3〉. TBSブリタニカ.
- ミゾレウミウシ, 小野篤司. (2004). 沖縄のウミウシ. ラトルズ.
- Chromodoris willani, Johnson R.F. & Gosliner T.M. (2012). Traditional taxonomic groupings mask evolutionary history: a molecular phylogeny and new classification of the chromodorid nudibranchs. PLoS ONE 7(4): e33479.
- Chromodoris willani, Layton K.K., Gosliner T.M. & Wilson N.G. (2018). Flexible colour patterns obscure identification and mimicry in Indo-Pacific Chromodoris nudibranchs (Gastropoda: Chromodorididae). Molecular Phylogenetics and Evolution. 124: 27-36. https://doi.org/10.1016/j.ympev.2018.02.008
A Kindle field guide by the site author
Kimoto N. (2026). Sea Slugs of Japan & the Indo-Pacific, 2nd Edition.
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Photos of Chromodoris willani
Tag:
Same Genus Nudibranchs
Similar Colors Nudibranchs
Academic Database
Sea slug observation data is available in international marine biodiversity databases.