Tayuva coerulescens (Bergh, 1888)

Description

A small discodorid, the largest preserved specimen 28 mm long, up to 17 mm wide and 6 mm high. In life the body is bluish-white, with the rhinophores light yellow bearing grey blotches; preservation alters the colour to a uniform dark brownish-grey, with the upper surface slightly darker. The body is the typical elongate-oval, flattened discodorid form, with a broad and thin mantle border. The entire dorsum is dotted with extremely fine, almost imperceptible, scarcely projecting nodules; the underside of the mantle border is even flatter with a fine showing-through spicule network. The rhinophore openings, strongly contracted, project with serrated edges; the rhinophore club bears 40-50 leaves. The gill opening projects papilla-like with a serrated edge; the gill consists of six tripinnate leaves; the anal papilla is sub-median with the renal pore beside it. The oral tentacles are finger-shaped; the mouth opens as a vertical slit. The foot is not narrow, with rounded anterior corners. The animal is somewhat stiff but not hard.

Distribution

Type locality: off Mauritius, Indian Ocean. Distributed across the western Indian Ocean.

Etymology

The Latin coerulescens is the present participle of caerulescere ("to become bluish"), meaning "becoming blue, bluish-tinted", in reference to the bluish-white live coloration.

Remarks

Originally described in Discodoris, later transferred to Tayuva.

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References

• Discodoris coerulescens, Bgh. n. sp., Bergh R. (1888). Nudibranchien vom Meere der Insel Mauritius. In: Semper C. (ed.), Reisen im Archipel der Philippinen. II. Wissenschaftliche Resultate. Bd. II, Abt. II (Malacologische Untersuchungen Bd. III), Heft XVI: 755-814. Wiesbaden: C.W. Kreidel's Verlag.
• ワギリウミウシ（仮称）, 小野篤司. (1999). ウミウシガイドブック. TBSブリタニカ.
• ワギリウミウシ（新称）, 小野篤司. (2000). ウミウシガイドブック. 第2版. TBSブリタニカ.
• Discodoris coerulescens, Terrence Gosliner, Ángel Valdés and David Behrens. (2015). Nudibranch and Sea Slug Identification Indo-Pacific. New World Pubns Inc.
• Tayuva coerulescens comb. nov., Fernández-Vilert R., Arnedo M.A., Salvador X., Valdés Á., Schrödl M. & Moles J. (2024). Shining disco: shedding light into the systematics of the family Discodorididae (Gastropoda: Nudibranchia). Zoological Journal of the Linnean Society. 203(1): zlae170. https://doi.org/10.1093/zoolinnean/zlae170