Suborder Aeolidina & Arminina
This is the smallest suborder of nudibranchs and includes the remaining Nudibranchia
which don't quite fit into the other categories.
This group has clusters or rows of long, finger-like cerata.
Many are prey specific which creates fluctuations in their
populations and locations as they follow their prey.
Flabellina verrucosa (Johnson, 1832)Red-gilled Nudibranchintertidal to 300m size to 10cmnorthern Washington to southern Alaska andcircumboreal, Sea of Japan and North AtlanticThis species is infrequently found intertidally.
Flabellina trophina (Bergh, 1894)Long-mouthed Aeolid
subtidal to 65m size to 50mm
central Oregon to southern Alaska; Sea of Japan
This species has a pronounced pointed snout and the cerata are
continuous along its back instead of in clusters.
(synonym - Flabellina fusca)
Flabellinidae photographed subtidallyFlabellina trilineata (O'Donoghue, 1921)Three-lined Aeolid
intertidal to 50m size to 36mm
northern Mexico to southern Alaska
This is infrequently found intertidally. It is distinguished
by it's orange tipped cerata and rhinophores and by the
three white lines extending the length of the body.
(previous name - Coryphella trilineata)
Cerberilla mosslandicaMcDonald and Nybakken, 1975Moss Landing Aeolidsubtidal size to 9mmsouthern California to southern BCThis species burrows in soft sediments.
This page last revised: 11-17-2012
Aeolidiidae all photographed intertidally
Aeolidia papillosa (Linnaeus, 1761)Shag-Rug Nudibranch *intertidal to 900m northern Mexico to central Alaska; Sea of Japan; circumboreal; and southern South America on both coasts size to 10cm
This species is occasionally seen intertidally.
It has the unique characteristic of storing the stinging cells,
from the anemones it feeds on, in its cerata for its own defense.
all photographed subtidally
attacking sea pens
Armina californica (Cooper, 1963)Striped Nudibranchintertidal
to 230m on sandy bottoms Panama to
northern Alaska size to 7cmThis species is infrequently found intertidally in the northwest.
Cuthona concinna (Alder & Hancock, 1843)Neat Aeolidsubtidal size to 15mmsouthern BC to northern Alaska; circumpolarThis is a very plain species
and may be cream to yellow.
(previous name - Trinchesia concinna)
Tergipedidae photographed subtidally
Catriona columbiana(O'Donoghue, 1922)British Columbia Aeolidintertidal to subtidal size to 20mmsouthern California to southernmost Alaska;South Africa; New Zealand; JapanThis species is very infrequently seen intertidally. It feeds on the hydroid Tubularia.
(synonyms - Catriona alpha, Cratena spadix)
Click on photo to enlarge. Scale line in photo equals 1cm unless otherwise specified.
* Species which are the most commonly encountered nudibranchs on the beach.
in the order Nudibranchia are the true sea slugs. The adult forms
have a complete absence of a shell and have externally exposed respiratory
Dirona pellucida Volodchenko, 1941
Translucent Dironaintertidal to subtidal size to 12cmcentral Oregon to northern Alaska;
Sea of Japan to RussiaThis is infrequently found intertidally.
White speckling on the lower body
distinquish it from D. albolineata.
(synonym - Dirona aurantia)