Janolus tricellariodes Pola & Gosliner, 2019

MORPHOLOGY

This species feeds on arborescent bryozoans of the genus Tricellaria. It is usually found on steep reef walls and pinnacles in areas where strong currents are present in 20–40 m.
Living specimens reaching 25 mm in length (Gosliner et al., 2008, 2015). Body broadest anteriorly, tapering to elongate posterior end of the foot extending well beyond notum. Rhinophores elongate with about 15 complete or incomplete transverse lamellae. Well-developed, convoluted caruncle (Figure 2e–g) present between rhinophores. Eyes appearing as two small black dots just behind rhinophores. Large, swollen cardiac area located near middle of notum. Pair of short, digitiform oral tentacles extending from either side of head. Cerata elongate, very globose centrally. Most cerata not entirely smooth, but with some tubercles. Cerata distributed over whole body, in 13–16 rows, with 4–5 cerata per row. Digestive gland inserting into most of the cerata at the base and branching within the papillae. Anteriormost cerata lacking extensions of digestive gland. Anus located mid-dorsally near posterior end of notum. Gonopore located on right side, in middle of body.

DISTRIBUTION

Western Pacific Ocean (Gosliner et al., 2015). This species is found in the Philippines (Debelius & Kuiter, 2007; Gosliner et al., 2008; present study), Okinawa, Japan and Indonesia (Gosliner et al., 2008).

ETYMOLOGY

The specific name refers to Tricellaria sp., the bryozoan on which it feeds.

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References

• トゲトゲウミウシ（仮称）, 益田一. (1999). 海洋生物ガイドブック.
• トゲトゲウミウシ（仮称）, 小野 篤司. (1999). ウミウシガイドブック.
• トゲトゲウミウシ（新称）, 小野 篤司. (2001).ウミウシガイドブック. 第二版.
• トゲトゲウミウシ, 益田 一. (2004). 海洋生物ガイドブック. 第7刷.
• トゲトゲウミウシ, 小野 篤司. (2004). 沖縄のウミウシ.
• Janolus sp. 8, Terrence Gosliner, Ángel Valdés and David Behrens. (2015). Nudibranch and Sea Slug Identification Indo-Pacific. New World Pubns Inc.
• コヤナギウミウシ属の仲間 Janolus sp. 5, 中野 理枝. (2018). 日本のウミウシ.
• Janolus sp. 8, Terrence Gosliner, Ángel Valdés and David Behrens. (2018). Nudibranch and Sea Slug Identification Indo-Pacific 2nd Edition. New World Pubns Inc.
• Pola M., Hallas J.M. & Gosliner T.M. (2019). Welcome back Janolidae and Antiopella: Improving the understanding of Janolidae and Madrellidae (Cladobranchia, Heterobranchia) with description of four new species. Journal of Zoological Systematics and Evolutionary Research. 57(2): 345-368., available online at https://doi.org/10.1111/jzs.12257