Like all dorid
nudibranchs (members of suborder Doridacea), this species has a circle
of gills around a mid-dorsal anus. Rostanga pulchra
large dorsal outgrowths other than the rhinophores
and gills but it does have tubercles
scattered all over the dorsum.
The gills can be completely retracted into sheaths. The color
red to orange-red, sometimes with a few tiny brown or black spots on
The overall shape is oval, though it may taper toward the
along the margins of the dorsum
may have white pigment. The rhinophores
have 10-12 vertically oriented leaves and end in slender papillae.
and gills are the same orange color as the dorsum,
although there may be white tips on the gills. Length to 1.6
(or to 3 cm in California?)
pulchra MacFarland, 1905
Common name(s): Red sponge nudibranch, Red sponge doris, Red
pulchra, approximately 1 cm long, on a sponge at Swirl
|(Photo by: Dave Cowles
How to Distinguish from
Similar Species: Aldisa
sanguinea, which lives from Oregon to Baja California and
and lives on red sponges, has perfoliate
Point Craven, Alaska
to the Gulf of California; Chile, Argentina
Intertidal to 102
On and around red sponges
feeds on, and is often found on, red sponges such as Acarnus,Esperiopsis,Ophlitaspongia,
its eggs in a tight orange circle on the sponges March to October (photo).
The larvae are planktonic for 30-45 days, then settle. An
with at least one prey sponge, Ophlitaspongia
pennata, can induce larvae to settle. It is
its orange pigment comes from the sponge. Adults can locate
to distant Ophlitaspongia
sponges by smell. Some individuals seem to stay quite close
area while others range for distant sponges. Predators may
the flatworm Notoplana
The cephalaspidean predatory nudibranch Navanax inermis is
repelled by secretions from Rostanga.
and Fairbanks, 1966
and Carlton, 1975
nd Brusca, 1978
and Snook, 1955
et al., 1980
and O'Clair, 1998
et al., 1985
General Notes and
abundances, unusual behaviors:
This individual is crawling across red algae in a tidepool.
Photo by Dave Cowles, July 2005
This 1/2 cm specimen was photographed by Dave Cowles at San Simeon, CA
This species lays red coils of eggs on the red sponge on which
it feeds. Photo by Dave Cowles in a tidepool, July 2012
This pair of nudibranchs on a sponge near the one shown above
with eggs are probably preparing to mate and lay eggs as well.
The closeup rhinophore views above and below show the structure of the rhinophores, with vertically oriented leaves terminating in a slender papilla.
(above) and side views (below) of the retractable gills. The gills have
a small piece of debris clinging to them. Animal is 14 mm long.
The dorsum is textured by small dorsal tubercles, as is visible in the view of the posterior dorsum behind the gills.
Authors and Editors of Page:
Dave Cowles (2007): Created original page
CSS coding for page developed by Jonathan Cowles (2007)