Eubranchus prietoi
Llera & Ortea, 1981

Order: NUDIBRANCHIA
Suborder: AEOLIDINA
Superfamily: AEOLIDINA
Family: Eubranchidae

DISTRIBUTION

Known from Atlantic coast from Arcachon, France to Dakar, Senegal.

PHOTO

'Saint Yves', Arcachon, Arcachon Basin. France. Atlantic Ocean. Depth: 9 -12 m. Length: 2 - 7 mm  20 June 2005. rocks with hydroids. Photographer: Marina Poddubetskaia Ossokine

This small eubranchid has a translucent body with scattered off-white, and brownish spots and patches. The cerata are transparent with off-white spotting, and the yellowish brown digestive gland shows through the ceratal wall. The cerata are arranged in 4 or 5 single rows down each side, with only one row in front of the heart. Llera and Ortea (1981) describe the anterior 2 rows on each side having a double row at the base of these anterior groups, but this is not evident in Marina Poddubetskaia's photos. The cerata often have three swellings, a small apical one, a large median one and a smaller basal one. There appears to be small whitish tubercles forming a ring around each swelling. There is often a darkish band below the uppermost swelling but this may just be because the ceratal wall at this point is transparent. The smooth  rhinophores are transparent with whitish spotting and two translucent brown bands, one near the tip and one near the base.

This species differs from other European species in having only a single ceratal row in front of the heart. Because of this, the dark brown precardiac digestive gland duct is very obvious through the dorsal body wall as a  dark brown V-shaped mark. Llera & Ortea (1981) report Eubranchus prietoi feeding on Plumularia setacea. Marina Poddubetskaia confirms this and reports seeing it on other hydroids as well. It is quite quite similar to in general appearance to Eubranchus doriae and Eubranchus exiguus, but it can be easily distinguished by the dark, Y-shaped, digestive gland duct visible through the body wall. Poddubetskaia also notes its similarity to Tergipes tergipes, but as she notes, in that species the cerata on each side are arranged in alternate rows rather than opposite each other. E. prietoi  grows to about 7 mm in length.

• Edmunds, M, & Kress, A. (1969) On the European species of Eubranchus (Mollusca Opisthobranchia). Journal of the Marine Biological Association, United Kingdom, 49(4): 879-912, Pls.1-2.
• Llera, E. M. and Ortea, J. A. (1981) Una nueva especie de Eubranchus (Mollusca: Nudibranchiata) del Norte de España. Bollettino Malacologico, 17: 265-270.

Authorship details
Rudman, W.B., 2005 (August 26) Eubranchus prietoi Llera & Ortea, 1981. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/eubrprie

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