Phyllidiella nigra (van Hasselt, 1824)

Description

Reaches about 63 mm in length. Ground colour black, with pink tubercles distributed evenly across the dorsum. Unlike most congeners, the tubercles are not arranged in distinct longitudinal rows and only rarely fuse with neighbouring tubercles, giving the dorsum a uniformly speckled appearance. Rhinophores black.

Distribution

Indian Ocean, western Pacific and South Pacific. Records include the Maldives, Thailand, Australia, Papua New Guinea, Malaysia, Vietnam, Indonesia, the Philippines, Japan, Palau, Pohnpei, Guam and New Caledonia. The type locality is Anyer Bay (Anjer-baai), west Java, Sunda Strait, Indonesia.

Etymology

The specific epithet nigra is the Latin feminine of niger, "black", referring to the dark ground colour. Van Hasselt's diagnosis describes the body as "e nigro olivaceo" — blackish-olivaceous.

Remarks

Originally described as Phyllidia nigra by van Hasselt in his Java mollusc letter (Bulletin des Sciences Naturelles et de Géologie, vol. 1: 244, 1824), based on a single specimen from Anyer Bay in the Sunda Strait. Van Hasselt regarded the species as "species rara" (rare). Subsequently transferred to the genus Phyllidiella Bergh, 1869 in a 1993 revision of the Phyllidiidae.

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References

• Phyllidia nigra, Hasselt J.C. van (1824). Extrait d'une lettre du Dr. J.C. Van Hasselt, à M. C.J. Temminck, sur les mollusques de Java (traduit du Algemeene Konst- en Letterbode 1824 par H. Boie). Bulletin des Sciences Naturelles et de Géologie (Férussac), Tome 1: 237-247.
• Phyllidiella nigra, Terrence Gosliner, Ángel Valdés and David Behrens. (2015). Nudibranch and Sea Slug Identification Indo-Pacific. New World Pubns Inc.
• クロイボウミウシ（新称）, 中野理枝. (2018). 日本のウミウシ. 文一総合出版.