Gosliner, Schaefer & Millen, 1999
Gulf of California, Mexico to Monterey County, California, USA.
Shag Rock, Santa Barbara Island, California, USA. July 19, 2003. Photo: Chris Grossman.
Doriopsilla gemela is similar in colour to D. albopunctata with small opaque white spots, but the mantle of D. gemela appears much smoother although it has some minute tubercles. It grows to 40 mm. Its rhinophores are yellow-orange to yellow and they have 7-10 lamellae. There are 5-7 bright orange or yellow bi- to tripinnate gills. The egg ribbon forms a flattened spiral of 3 whorls, and the larvae are lecithotrophic. It differs from D. albopunctata in having deep yellow or yellow-orange gills whereas D. albopunctata has white or pale yellow gills. There are fewer rhinophore lamellae in D. gemela, and the larger mantle tubercles of D. albopunctata contain glands while the small ones of D. gemela don't. The larval development type and egg ribbons are also quite different.
Baptodoris mimetica Gosliner, 1991 is also very similarly coloured. D. albopunctata differs in having a relatively soft & fleshy body while B. mimetica is more rigid and the mantle is covered with microscopic caryophyllidia. The gills of B. mimetica are held more erect, and unlike species of Dendrodoris and Doriopsilla, Baptodoris mimetica has a head and oral tents. There are of course many anatomical differences.
Despite these many apparent differences, it is not always easy to distinguish these three species from photographs.
• Gosliner, T.M. (1991) Four new species and a new genus of opisthobranch gastropods from the Pacific coast of North America. The Veliger, 34(3): 272-290.
• Gosliner, T. M., Maria C. Schaefer, & Sandra V. Millen. (1999) A new species of Doriopsilla (Nudibranchia: Dendrodorididae) from the Pacific Coast of North America, including a comparison with Doriopsilla albopunctata (Cooper, 1863). The Veliger, 42(3): 201-210.
Rudman, W.B., 2003 (July 29) Doriopsilla gemela Gosliner, Schaefer & Millen, 1999 . [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/dorigeme