Armina occulta Mehrotra, Caballer & Chavanich, 2017

Description

From the original diagnosis (Mehrotra et al., 2017):

Armina occulta n. sp. is characterized by its black dorsum with white notum narrowed forming two transverse dark bands, divergent and bifurcated posteriorly; orange mantle edge; black foot with a thick marginal band of deep blue; rhinophores deep blue with yellow tips, and a black subterminal band.

Distribution

Type locality: Koh Tao, Gulf of Thailand. A 2017 study recorded specimens from soft sediment habitats at depths of 13–25 m, where the species feeds on the sea pen Virgularia sp.

Etymology

Verbatim from the original description (Mehrotra, Caballer Gutierrez & Chavanich, 2017):

Armina occulta from the Latin word occulta, meaning hidden, because it has been confused with A. scotti n. sp. (as Armina semperi) in Thailand, with which it is sympatric.

Remarks

A member of the family Arminidae. A 2017 study considered Armina occulta morphologically closest to Armina major Baba, 1949 and Armina magna Baba, 1955 but distinct in size and in jaw and radular characters. From sympatric Armina scotti it is distinguished by being roughly twice as large, by the orange mantle edge, the white notal ridges divergent and bifurcated posteriorly, deep blue rhinophoral stalks, a black foot with a deep blue marginal band, an oral veil with bright orange edge and two deep blue submarginal bands, the absence of the H-shaped black design on the head, and a stylet-bearing penis.

---

References

• Armina sp. 3, Helmut Debelius, Rudie H. Kuiter. (2007). Nudibranchs of the World.
• Armina sp. 2, Gosliner T.M., Behrens D.W. & Valdés Á. (2008). Indo-Pacific Nudibranchs and Sea Slugs: A field guide to the world's most diverse fauna. Sea Challengers Natural History Books, 426 pp.
• Armina sp. 2, Terrence Gosliner, Ángel Valdés and David Behrens. (2015). Nudibranch and Sea Slug Identification Indo-Pacific. New World Pubns Inc.
• Armina occulta, Mehrotra R., Caballer Gutierrez M. & Chavanich S. (2017). On the genus Armina (Gastropoda: Heterobranchia: Nudibranchia) in Thailand. Marine Biodiversity. 47(2): 549-559. https://doi.org/10.1007/s12526-017-0691-6
• ルリフチハスエラウミウシ（新称）, 中野理枝. (2018). 日本のウミウシ. 文一総合出版.