Armina comta (Bergh, 1880)

Description

A medium-sized arminid about 30 mm in body length. The living dorsum is black with about 30 pale-yellow longitudinal lines, alternating thicker and thinner stripes. The dorsal margin, foot edge and the rim of the oral veil (tentacular shield) are bordered with pale yellow. The carunkel between the oral veils bears a row of small papillae — four unequal papillae (occasionally bifid) on each side of the shield, and a further three stout papillae set on each side of the rhinophoral pit. This papillar arrangement is a useful diagnostic character. The rhinophores are streaked with black, with pale-yellow tips. The gill runs along most of the dorsum, with about 50 leaves on each side.

Distribution

Type locality: off Nagasaki, Japan (M. japonicum). The original description was based on a single specimen collected by Dr A. v. Roretz off Nagasaki in 1876. Subsequent records show that the species is widely distributed in the tropical to subtropical Indo-West Pacific, with reports from Japan, China, the Philippines and Indonesia. Specimens up to 100 mm have been observed in life.

Etymology

The specific epithet comta is the feminine form of Latin comptus, meaning "adorned, neatly arranged, elegant", in reference to the orderly pattern of yellow longitudinal stripes on the black dorsum.

Remarks

Originally described by Bergh as Pleurophyllidia comta n. sp. Pleurophyllidia Meckel is now treated as a synonym of Armina Rafinesque, 1814; the species has accordingly been transferred to Armina, with the parentheses in the author citation reflecting this generic change. It is closely related to the boreal Armina loveni but differs in the arrangement of the carunkel papillae and details of the radula and reproductive system.

---

References

• Pleurophyllidia comta Bgh. n. sp., Bergh R. (1880). Beiträge zur Kenntniss der japanischen Nudibranchien. I. Verhandlungen der kaiserlich-königlichen zoologisch-botanischen Gesellschaft in Wien. 30: 155-200, Taf. I-V.
• 高岡生物研究会. (2002). 日本海のウミウシ. 第2版.