Janolus mirabilis Baba & Abe, 1970
- Location
- Sunabe Water Treatment Plants, Okinawa Island (Chatan and Southern area), Okinawa, Japan
- Date
- 2015/04/26
- Length
- 4mm
- Depth
- 8.0m
- Water temperature
- 23.0℃
Description
Living animal about 7 mm in length. Rhinophores distinctly perfoliated above, with a single crest between the two rhinophores. Branchial papillae fall off easily; in life they are covered with acutely pointed tubercles near the tip and stand in a single row on the antero-lateral margins of the body, with a small number also on the postero-lateral margins. The bare space of the back is covered with minute tubercles. Anus near the rear end of the mantle in the median line; the genital orifice opens on the right side below the anterior end of the pericardial prominence. Foot broad with rounded corners; no tail crest. General integument translucent ashy yellow, the back tinged with dark brown; rhinophores dark brown below, opaque white at tip; inter-rhinophorial crest black; branchial papillae tipped with opaque white, the liver diverticulum within yellowish; tip of oral tentacles whitish; tail and sole spotted here and there with opaque white.Distribution
Type locality: Abugashima, Toyama Bay (Japan Sea coast of Honshu, Japan). Long known only from a single Japanese specimen, the species was rediscovered at Heron Island on the Great Barrier Reef, with additional records from East Africa establishing a broad Indo-West Pacific distribution.Etymology
The specific epithet mirabilis is general Latin for "wonderful, astonishing", consistent with the original description, which notes that the species is exceptionally striking among Janolus.Remarks
The species is placed in Janolus on the combination of an inter-rhinophorial crest, tuberculated branchial papillae and the absence of serial denticles on the edges of the jaw plates. Members of Janolidae feed on bryozoans, unlike most other nudibranchs.References
- Karajishi-umiushi, 1970. Baba, Kikutaro & Takeo Abe. Two New Species of Janolidae from Toyama Bay, Japan (Gastropoda: Nudibranchia). The Veliger 13(1): 63-66
- カラジシウミウシ, 小野篤司. (1999). ウミウシガイドブック. TBSブリタニカ.
- 高岡生物研究会. (2002). 日本海のウミウシ. 第2版.
- カラジシウミウシ, 小野篤司. (2004). 沖縄のウミウシ. ラトルズ.
- カラジシウミウシ, 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.
Kindle Edition
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Photos of Janolus mirabilis
Same Genus Nudibranchs
Similar Colors Nudibranchs
Academic Database
Sea slug observation data is available in international marine biodiversity databases.