Tritonia diomedea
Bergh, 1894

Family: Tritoniidae


West Coast of North America from Aleutian Islands, Alaska to Bay of Panama. (also Japan).


Upper: In sand near Monterey Breakwater, California, 18m. Approx 150mm long. Photo: Clinton Bauder.
Lower: Monterey Bay, California, at about 200 feet. Approx 75mm long. Photo: Steve Johnston.

Broad tritoniid in which the foot is wider than the dorsum. The oral veil is wider than the foot and has a series of digitiform sensory tentacles along the anterior edge. There are 20-30 small branched gills along the edge of the dorsum. The body ranges in colour from a translucent white, through pink to quite a deep red. There is a narrow opaque white line along the edge of the foot, dorsum, edge of the rhinophore sheath and posterior edge of the oral veil.

This species lives in sand and feeds on sea pens (Pennatulacea) such as Renilla. It grows to approx 200mm in length, and is found from the shallow sublittoral to 750m.

• Bergh, R. (1894) Reports on the dredging operations off the West Coast of Central America to the Galapagos, to the West Coast of Mexico, and in the Gulf of California, in charge of Alexander Agassiz, carried on by the U.S. Fish Commission Steamer "Albatross", during 1891, Lieut. Commander Z.L.Tanner, U.S.N., Commanding. XIII. Die Opisthobranchien. Bulletin of the Museum of Comparative Zoology 25(10): 125-233.

Authorship details
Rudman, W.B., 1998 (June 5) Tritonia diomedea Bergh, 1894. [In] Sea Slug Forum. Australian Museum, Sydney. Available from

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