California, USA to Baja California, Mexico.
Mono Lobo wall, Carmel, California, approx 20M. Length 20mm, February 2001. Photo: Clinton Bauder.
Translucent white or yellowish with aggregations of dark brown spots in the dorsal midline, one just in front of the gills and one just behind the rhinophores. mantle covered in long tapering papillae. Grows to about 3cm.
Lance, J.R. (1966). New distributional records of some northeastern Pacific Opisthobranchiata with descriptions of two new species. The Veliger, 9(1): 69-81, text figs. 1-12Authorship details
Rudman, W.B., 2001 (March 5) Thordisa bimaculata Lance, 1966. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/thorbima