How to Distinguish from Similar Species: The large dark rings make this dorid easy to distinguish. However, what formerly was considered a variant of this species is now recognized by molecular and morphological criteria as a separate species, Diaulula odonoghuei. D. odonoghuei has mainly spots (occasionally rings) on both the central part and the edges of its dorsum. The spots in D. odonoghuei both grow and increase in nunber with age, and range in count from around 23 to 234 (mean = 76). It is also similar to another species, Discodoris heathi, which also has spots instead of rings. Geographical Range: Vancouver Island south to Puerto Penasco, Mexico Depth Range: Low intertidal and subtidal to 35 m. Lindsay et al. (2016) state that this species is almost exclusively subtidal in the Pacific Northwest but is often intertidal from northern California south. Habitat: Rocky intertidal, surge channels Biology/Natural History: Feeds on Halichondria, Haliclona, Myxilla, and Petrosia sponges. The egg ribbon is narrow, white, attached in an oval spiral under rock ledges by one margin. According to Baltzley et al., (2011), many gastropods, including this species, have a special network of pedal ganglia in their foot which assists in crawling. The two main neurons involved produce pedal peptides which elicit an increase in the rate of beating of cilia on the foot, resulting in crawling.
References:Dichotomous Keys:Kozloff 1987, 1996 Smith and Carlton, 1975 General References:
Scientific Articles:
Lindsay, Tabitha, Julie Kelly, Anton Chichvarkhin, Sean Craig, Hiroshi Kajihara, Joshua Mackie, and Angel Valdes, 2016. Changing spots: pseudocryptic speciation in the North Pacific dorid nudibranch Diaulula sandiegensis (Cooper, 1863) (Gastropoda: Heterobranchia). Journal of Molluscan Studies 82:4 pp 564-574. doi:10.1093/mollus/eyw026 General Notes and Observations: Locations, abundances, unusual behaviors:
Authors and Editors of Page: Dave Cowles (2005): Created original page |