Doriopsilla janaina from Mexico

April 17, 2002
From: Alicia Hermosillo

Dear Dr. Rudman,
I am sending you information and photos on a species of dorid, Doriopsilla janaina, that is not in your species list yet. I hope it will be of interest to someone.

Data: March 7th, 2002
Playa Mismaloya, Bahia de Banderas, Jalisco and Nayarit, Pacific Coast of Mexico
25 mm in length. On large rocks to a depth of 70 feet (personal observation).

This species is rather common in my area of study (I have seen 24 in my last 7 dives). When it is on its habitat, it is really cryptic, in order to find it I need to see the egg masses first (which on the other hand, are of a bright orange and very easy to spot) and then look around for D.janaina really hard. Hopefully soon I will be able to buy my housing and send you pictures of D. janaina underwater with its eggs, but for now this pictures will have to do.

I thank my friend Angel Valdes for information on this species, which I learned has a chemical compound (olepuapane) used as a natural insecticide (Okuda et al., 1983).

• Marcus, Ev. y Marcus, Er. 1967. Tropical American Opisthobranchs. Studies in Tropical Oceanography, 6: 3-137, pl. 1.
• Gosliner, T.M. 1991. The opisthobranch gastropod Fauna of the Galapagos Islands. In: James, M.J. (ed.): Topics in Geobiology 8(13): 281-305. Galapagos Marine Invertebrates: taxonomy, biogeography, and evolution in Darwin's Islands. Plenum Press: New York. Xiv+474 pp.
• Okuda, R.K., Scheuer, P.J., Hochlowski, J.E., Walker, R.P. & Faulkner, D.J. 1983. Sesquiterpenoid constituents of eight porostome nudibranchs. Journal of Organic Chemistry, 48: 1866-1869.

Alicia Hermosillo

Hermosillo, A., 2002 (Apr 17) Doriopsilla janaina from Mexico. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Ali,
Thanks for these photos. I am sure they will interest many people. The few photos I have seen of this animal show it as quite a deep orange colour so your photos show an interesting variation in its colour. I look forward to some photos it on its sponge with eggs. As you have discovered, egga are an excellent clue to finding cryptic nudibranchs.
Best wishes,
Bill Rudman

Rudman, W.B., 2002 (Apr 17). Comment on Doriopsilla janaina from Mexico by Alicia Hermosillo. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from