Crimora lutea Baba, 1949
Description
A tiny Polyceridae, body length about 3 mm. The mantle margin is sharply demarcated from the body sides. Around the mantle margin, 20-25 small processes (single or apically bifid) are arranged in a row; similar processes (about 9) are scattered on the central dorsum, with 3-4 more on the tail ridge. The body sides are smooth. Rhinophore sheaths present. Three simple gills, with no gill pocket. The body is yellow, with all the small processes black. Both jaw and labial disc absent. The radula is highly differentiated, with formula 28×6-7.6.2.0.2.6.6-7. The outermost teeth are elongate and brush-like, densely arranged; the intermediate laterals (6 rows) are scale-like.Distribution
Type locality is off Kurosaki, Sagami Bay (15 m depth, August 1939) and off Hasaki, Sajima Island (17 m depth, August 1940). The original description (Baba, 1949) records the species only from Sagami Bay.Etymology
The specific epithet lutea is Latin for yellow. The original description does not give an explicit etymology paragraph; the descriptive sense reflects the bright yellow body colour. The Japanese name "Yaguruma-umiushi" (pinwheel sea slug) likens the row of marginal processes to a pinwheel.Remarks
A generic feature of the species is the highly differentiated radula with brush-like outer lateral teeth.References
- Crimora lutea (genus context), Alder J. & Hancock A. (1862). Descriptions of a new genus and some new species of naked Mollusca. Annals and Magazine of Natural History. (3)10(57): 261-265.
- Crimora lutea Baba, 1949, Baba K. (1949). Opisthobranchia of Sagami Bay collected by His Majesty the Emperor of Japan (相模湾産後鰓類図譜). Iwanami Shoten, Tokyo. 4+2+194+7 pp., pls. 1-50.
- ヤグルマウミウシ, 小野篤司. (2004). 沖縄のウミウシ. ラトルズ.
- ヤグルマウミウシ, 中野理枝. (2004). 本州のウミウシ. ラトルズ.
- ヤグルマウミウシ, 小野篤司 & 加藤昌一. (2009). ウミウシ. 誠文堂新光社.
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 Crimora lutea
Same Genus Nudibranchs
Similar Colors Nudibranchs
Academic Database
Sea slug observation data is available in international marine biodiversity databases.