10m of water on the sand near the Monterey Breakwater, California, USA. Approx 20mm long.
Photo: Sami Laine
The mantle is brown with blotches and spots of white and black. Much of the mantle is covered in high pointed translucent papilla which are greyish basally and whitish in the upper half. Dave Behrens in Pacific Coast Nudibranchs notes that one of its most distinctive characteristics is the pungent odour of cedar it gives off when handled. it feeds on bryozoans, and grows to approx 20mm long.
Behrens, D., 1991 Pacific Coast Nudibranchs.
MacFarland, F.M. (1905) A preliminary account of the Dorididae from Monterey Bay, California. Proceedings of the Biological Society of Washington 18: 35-54.
MacFarland, F.M. (1905) Opisthobranchiate mollusca from Monterey Bay, California, and vicinity. Bulletin of the Bureau of Fisheries, 25: 109-151.
Rudman, W.B., 2002 (October 29) Acanthodoris brunnea MacFarland, 1905. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/acanbrun