Author: Undescribed

Order: Nudibranchia  Family: Fionidae

Maximum Size: 20 mm

Sightings: Bali, Indonesia

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Eubranchus sp. 27
The rhinophores are dark pigmented with small spots of opaque white pigment randomly scattered over them. The oral tentacles however are translucent, with similar white spotting. The cerata are long and spindly each with three annular rings consisting of tubercles projecting out to twice the diameter of the ceratal stalk. The apices are swollen bulbs that reduce to a conical tip. All are covered in brown and white specks. The digestive diverticulum within the cerata are visible and white in colour.

This species exhibits some similarities to our Eubranchus sp. 10 from the Sunshine Coast, our Eubranchus sp 22 from the Philippines, our Eubranchus sp. 25 from Indonesia and our Eubranchus sp. 26 from Indonesia. The Eubranchus sp. 26 of NSSI, 2018 and the described Eubranchus putnami Cunha et al., 2023 from the Maldives, Indian Ocean, are also somewhat similar.

We believe there is a clade of taxonomically cryptic species involved here.

The image of Eubranchus putnami in the paper is poor and the description is limited to almost confusing. The description is based upon a single 7 mm specimen.  Additionally, the authors of the paper state:
“Somehow similar-looking morphotypes have been reported …. and a molecular study of those throughout the distribution is required to further ascertain their status.”

Therefore in view of that statement, the different localities to the holotype and the differences we have observed we are keeping separate, for now, those specimens with contradictory external morphological features. Should future work show them all to highly variable examples of the one species we will then post them as those variations.

David A. Mullins – April 2024

References:
– Gosliner, T. M., Valde ́s, A ́. & Behrens, D. W. (2018). Nudibranch & Sea Slug Identification – Indo-Pacific, 2nd Edition. New World Publications, Jacksonville, Florida, USA.

– Cunha, T. J., Fernández-Simón, J., Petrula, M., Giribet, G. & Moles, J. (2023) Photographic Checklist, DNA Barcoding, and New Species of Sea Slugs and Snails from the Faafu Atoll, Maldives (Gastropoda: Heterobranchia and Vetigastropoda). Diversity 2023, 15, 219.