Oyster Bay, Dar es Salaam, Tanzania, April 1975. 35mm long alive. PHOTOS: Bill Rudman.
Hypselodoris nigrolineata is rather similar in colour to the Western Pacific species Hypselodoris maritima. H. nigrolineata differs in having a purplish mantle border, blue in H. maritima, and in having diffuse black patches between the purple border and the black lined central region. No similar patches occur in H. maritima. One other major external difference is that in H. nigrolineata the gills are a translucent orange while in H. maritima they are white with orange edging. At present H. nigrolineata is known only from East Africa.
•Rudman, W.B. (1977) Chromodorid opisthobranch Mollusca from East Africa and the tropical West Pacific. Zoological Journal of the Linnean Society 61: 351-397.
•Rudman, W.B. (1982) The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: Chromodoris quadricolor, C. lineolata and Hypselodoris nigrolineata colour groups. Zoological Journal of the Linnean Society 76: 183-241.
Rudman, W.B., 2000 (May 1) Hypselodoris nigrolineata (Eliot, 1904). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/hypsnigrol