Jorunna ramicola M. C. Miller, 1996

Description

Body oval to elongate, with the dorsum covered by caryophyllidia about 400 µm in length. Each caryophyllidium has an elongate base, long spicules and a long ciliated tubercle. The background colour is pale grey to light brown, with patches of light grey to light brown scattered over the dorsum and an aggregation of minute dark-brown spots concentrated near the centre of the notum. The rhinophores are pale grey speckled with dark brown spots, white at the apex. The branchial leaves are dark grey. White spots are present around the mantle margin, and the rhinophoral and branchial sheaths bear small white glandular structures. Thick, almost rectangular jaw elements are present, a feature that distinguishes this species from some of its congeners.

Distribution

Indo-West Pacific. Type locality: north-western Kawau Islands, New Zealand. The range has subsequently been extended well beyond New Zealand into the central Indo-West Pacific, with records from Madagascar, the Philippines, Papua New Guinea and Indonesia.

Etymology

The specific epithet ramicola derives from the Latin ramus ("branch") and colere ("to inhabit"), reflecting the species' association with branching substrates such as algae and hydroids.

Remarks

Jorunna ramicola is distinguished from other Jorunna species by the combination of irregular brown to pale grey patches on the dorsum and the presence of well-developed jaw elements. Most other Indo-Pacific congeners differ either in lacking jaw elements (Jorunna rubescens, Jorunna funebris, Jorunna parva) or in details of the radular tooth shape (Jorunna pantherina, Jorunna alisonae).

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References

• Jorunna ramicola n. sp., Miller M.C. (1996). The dorid nudibranch genus Jorunna Bergh, 1876 (Gastropoda: Opisthobranchia) in New Zealand. Journal of Natural History, 30: 1095-1109.
• Jorunna ramicola Miller, 1996, Camacho-Garcia Y.E. & Gosliner T.M. (2008). Systematic revision of Jorunna Bergh, 1876 (Nudibranchia: Discodorididae) with a morphological phylogenetic analysis. Journal of Molluscan Studies. 74(2): 143-181. https://doi.org/10.1093/mollus/eyn002
• Jorunna ramicola, Terrence Gosliner, Ángel Valdés and David Behrens. (2015). Nudibranch and Sea Slug Identification Indo-Pacific. New World Pubns Inc.
• フイリビロードウミウシ（新称）, 中野理枝. (2018). 日本のウミウシ. 文一総合出版.