Eubranchus farrani
(Alder & Hancock, 1844)

Order: NUDIBRANCHIA
Suborder: AEOLIDINA
Family: Eubranchidae

DISTRIBUTION

Northeastern Atlantic from Norway to western Mediterranean.

PHOTO

Upper: Sete, étang de Thau, Mediterrnaena coast of France, March 2000, depth: 5m, size: 1cm. Photo: J-P. Bielecki.
Lower: approx. 10mm long, crawling on a kelp frond at 7 metres in NW Scotland. PHOTO: Jim Anderson. See Scottish Nudibranchs website.

This species has in the past been confused with Eubranchus tricolor but E. farrani is quite distinct, being more slender, smaller with fewer cerata of less compressed shape and different colour patterns.

The maximum length of the animal is 20 mm (23 mm in the Bay of Naples, according to Schmekel & Portmann, 1982). The body is typically white or grey-white, with orange-tipped rhinophores and oral tentacles (sometimes with white apices), with scattered orange spots and blotches on the dorsum, and white inflated cerata having a conspicuous sub-terminal orange or yellow ring. Occasional variants show individual exaggeration of certain markings. The entire body, cerata and all, may be of a beautiful golden hue. In others there may be brown patches on the body, and in one specimen (from Pembrokeshire) nearly the whole body was dark chocolate brown in colour (approaching the Form B of Edmunds & Kress). Other specimens may have orange blotches ringed with blue (Garstang, 1980; Farran, 1903), and the juveniles may exhibit no colour at all other than the pale brown or salmon pink hepatic contents of the cerata.

The cerata are arranged in up to 10 diagonal rows, of up to 5 cerata in each half-row. Their shape may be variable from minute to minute but it can always be seen that they are moderately inflated.

See Bernard Picton's message below, and his website for further information.

Reference:
• Edmunds, M. & Kress, A. (1969) On the European species of Eubranchus (Mollusca Opisthobranchia). Journal of the Marine Biological Association of the United Kingdom, 49: 879-912.
• Thompson, T.E. & Brown, G.H. (1984) Biology of Opisthobranch Molluscs, Vol 2. Ray Society: London.

Authorship details
Rudman, W.B., 2003 (October 14) Eubranchus farrani (Alder & Hancock, 1844). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/eubrfarr

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