As a Dendronotacean, this
species has its anus on the right side (on an anal papilla (photo),
dorsal cerata besides the rhinophores, and the clavus of the
is fully retractable into a sheath. D. iris
has two longitudinal
dorsal rows of very bushy cerata which have brick-red, yellow, purple,
orange, or white tips. The gut projects into only the most
pair of cerata. The rhinophores are very large and somewhat
in shape to the cerata, and the clavus extends from an anterior shelf
them--not obvious at first (photo).
sheath of the clavus is drawn out into several branched papillae that
it look crownlike. The large rhinophore stalk has 3-6 bushy
along its posterior border (photo).
species has a small oral veil with 4 pairs of oral papillae.
a white line around the edge of the foot, but has few or no white
spots (though the gonopore in this individual is ringed in
Can get up to 30 cm long, averages 6-10 cm, and is one of the largest
is America. Color is variable, often a shade of salmon-red or
purple but may be gray or pale as in this individual.
How to Distinguish from
D. albopunctatus has a large, wide oral veil and
spots. Other Dendronotus, such as D.
diversicolor, have no row of bushy projections
along the posterior
border of the rhinophore stalk.
Aleutian Islands to Los Coronados Island, Baja California.
Mostly subtidal, down
to 200 m. Sometimes seen on the surface over deep water, or
Mostly benthic on soft bottoms.
feeds on the tubedwelling anemone Pachycerianthus fimbriatus,
on Nemertean worms. Besides its radula,
it has large
jaws for clipping tentacles off the anemone, and leaves the anemone
as if it has had a bad haircut. The nudibranchs are sometimes
into the tube when the anemone retracts, but do not seem to be harmed
this. Predators include Pycnopodia
helianthoides. This nudibranch is very
active (see movie)
and can readily swim by gyrating the body. Eggs are laid in
strings (photo), often on the
tubes of their prey.
The heart of this individual was large, and the heartbeat was easily
through the dorsal surface (see movie).
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
neurons involved produce pedal peptides which elicit an increase in the
rate of beating of cilia on the foot, resulting in crawling.
and Fairbanks, 1966 (as D. giganteus)
and Carlton, 1975
and Snook, 1955 (as D. giganteus)
and Mills, 1998
Michael J., Allison Serman, Shaun D. Cain, and Kenneth J. Lohmann, 2011.
Conservation of a Tritonia
pedal peptides network in gastropods. Invertebrate Biology
130: 4 pp. 313-324
General Notes and
Observations: Locations, abundances,
The white-ringed gonopore on the right side, and the anal papilla
colored, to the right of the gonopore and benind and below the right
can be seen in this photo.
Photo by Dave Cowles, August 2005
The rhinophores (left shown here) have a series of projections on the
posterior side. The clavus is perfoliate, retractable, and
from an anterior shelf. It has a crownlike ring of
Photo by Dave Cowles, August 2005
The eggs are laid in gelatinous white strands, which are often attached
to the tubes of their anemone prey.
This nudibranch is very active, rapidly swirling its cerata around
when it crawls or swims. Click here
for a movie of the animal waving its cerata.
The heart of this nudibranch is large and easily seen beating through
the dorsal surface. Click here
for a movie of the heartbeat.
Authors and Editors of Page:
Dave Cowles (2005): Created original page