Palio nothus
(Johnston, 1838)

Suborder: DORIDINA
Family: Polyceridae


British Isles north to Arctic Circle and across to Nth America (Picton & Morrow, 1994)


under Mumbles Pier, Swansea, UK. Feeding on Bowerbankia sp. October 2002 Photo: Helen Marshall.

Dark brown to olive green body with pale translucent brown or clear conical tubercles. The lamellate rhinophores and tripinnate gills (numbering up to 5) are translucent with a brownish tinge. The frontal margin of the mantle is slightly bilobed and bears a number of short, fingerlike, pale brown papillae. Larger, club-like, pale papillae are clustered on the mantle edge, alongside the gills. The sides of the body are similar in colour to the mantle, the tubercles being lower and rounded in shape. This species has often been confused in the literature with Palio dubia. It grows to 20mm in length and feeds on species of the arborescent bryozoan Bowerbankia.

• Picton, B.E. & Morrow, C.C. (1994} A Field Guide to the Nudibranchs of the British Isles. 143pp. Immel Publishing: London.
• Thompson,T.E. (1988) Molluscs: Benthic Opisthobranchs (Mollusca: Gastropoda). E.J.Brill / Dr W.Backhuys. 356pp.

Authorship details
Rudman, W.B., 2003 (June 5) Palio nothus (Johnston, 1838). [In] Sea Slug Forum. Australian Museum, Sydney. Available from

Related messages

Palio nothus from Lundy Island, Devon, U.K.

September 12, 2008
From: Judith Oakley

Hi Bill
Recently found Palio nothus and spawn amongst Corallina officinalis turf from low shore rockpools on Lundy Island, Devon, United Kingdom. A new species for me.

Best wishes
Judith Oakley
Oakley Intertidal Marine Education & Outreach

Oakley, J., 2008 (Sep 12) Palio nothus from Lundy Island, Devon, U.K.. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Thanks Judith,

Best wishes,
Bill Rudman

Palio nothus from Wales

June 5, 2003
From: Helen Marshall

Hello Bill,
Whilst browsing through your Species List, I noticed that you didn't have any pictures of Palio nothus. The P. nothus photographed was collected in October 2002 under Mumbles Pier, Swansea, UK. They were found feeding on Bowerbankia sp. Hope they can be used to create a new section for P. nothus!
Helen Marshall

Marshall, J., 2003 (Jun 5) Palio nothus from Wales. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Thanks Helen,
I am more than happy to fill any vacancy in the List. This species has a very confused history, often being misidentified with Palio dubia.
Best wishes,
Bill Rudman