How to Distinguish from Similar Species: No other nudibranch-like animal in this area is white, with a lateral sheetlike extension above the foot and only one gill on the right side. Berthella californica is very similar but lives in California and south. Several dorid nudibranchs such as Doris odhneri look superficially similar but they have no lateral flap and their gills are a circle on the dorsum. Tylodina fungina is another Notaspidean, found in southern CA, but it is bright yellow. Note: Until recently this species was regarded to be Berthella californica. Ghanimi et al., 2020 showed that it is a different species, B. chacei.
Geographical Range: Point Craven, Alaska to Monterey, California; Pacific coast of Siberia, and Japan
Biology/Natural History: This uncommon but striking species apparently preys on ascidians and perhaps on sponges. Little is known about this species. Some members of this family can repel predators with extremely strong acid secretions from glands in the dorsum.
LaForge and Page studied B. chacei
species lays its eggs in a coiled ribbon attached to the substrate
one edge. The egg ribbon is white, about 1 cm wide, and 1 mm
The egg capsules in the ribbon are oval, around 1.6 or 1.7 mm wide, and
contain 1-2 eggs each. At 11-12 C the eggs hatched as veliger
in 19 days. Its developmental pattern resembles that of
more closely than does that of other pleurobranchoideans which have
studied. They also discovered that the snail-like shell which
larva has only becomes bilaterally symmetrical late in
Some of the events that occurred when the larva settled and
into the adult form included a rapid expansion of the mantle over the
so that the shell became internal. They also lost the large
velar lobes and began growing the rhinophore and oral veil.
also appeared to have an ospradium (chemosensory organ), though the
Kozloff 1987, 1996 (as Berthella californica)
Smith and Carlton, 1975 (as Berthella californica)
LaForge, Nicole L. and Louise R. Page, 2007. Development of Berthella californica (Gastropoda: Opisthobranchia) with comparative observations on phylogenetically relevant characters among nudipleuran opisthobranchs. Invertebrate Biology 126(4): 318-334 (Note: The species examined in this study is now known to have been B. chacei).
General Notes and Observations: Locations, abundances, unusual behaviors:
We have not often seen this animal around Rosario.
Authors and Editors of Page:
Dave Cowles (2005): Created original page