Quite common in the British Isles. Also reported from northern Spain and southern Norway.
Locality: Barmore Island, Loch Fyne, 12 m, Scotland, NE Atlantic, 31 August 2008, Boulder slope in sea loch. Length: 30 mm. Photographer: Jim Anderson.
The animal is a translucent cream or pinkish colour with dark brown or blackish mottling dorsally, usually more concentrated at the front of the body. There are a number of simple tubercles along each side of the body, each with a black tip. The cerata are large and have up to 6 circlets of tubercles, each tubercle having a black spot at its tip.
For the genus Doto pinnatifida is a relatively large species, growing to about 30 mm in length. It feeds exclusively on the calyptoblastic hydroid Nemertesia antennina.
Picton, B. E. and Morrow, C. C. (1994) A Field Guide to the Nudibranchs of the British Isles. London, Immel Publishing Ltd. 143pp.
Thompson, T. E. (1988) Molluscs: Benthic Opisthobranchs (Mollusca: Gastropoda). Leiden, The Linnean Society of London. 1-356.
Rudman, W.B., 2008 (September 23) Doto pinnatifida (Montagu, 1804). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/dotopinn