The eolid nudibranchs do not have specialized naked gills like the dorids. Instead, they usually have multiple paired rows of dorsal processes called cerata. While they do greatly increase the surface area of the nudibranch for respiration, they often also function in defense. Most eolids are specialized feeders on cniderians, otherwise known as corals and their relatives. Cniderians usually have stinging cells called nematocysts to catch prey or try to deter predation. This defense doesn't keep them from being eaten by nudibranchs, but many of the nudibranchs are able to take those nematocysts from their prey and use them in their own defense. They somehow keep from digesting the nematocysts they ingest along with their prey's tissue and move those stinging cells through branches of the digestive system that extend up into the cerata. There, in the tips of the cerata, the nematocysts are put into place and cause the nudibranch to become as effective at stinging potential predators, usually fish, as are the cniderians themselves. Some eolids eat hydroids, others eat anemones or hard or soft corals. One even eats the dreaded Portuguese man-o-war. Some, however, eat harmless prey without nematocysts, and these species often rely on camouflage to protect themselves. As in the other nudibranch groups, there is some fascinating biology going on behind the scenes that makes the eolids much more than just attractive photo subjects.
In the Marshalls, many eolids are small and scarce. Lots of species max out at less than 10mm, and at times the resolution of the photos reachable through this page is not ideal. In addition, there are a number of species we have recorded here for which we do not have pictures. With luck we will run across more specimens and be able to post photos of more species as time goes on.
It is worth noting here that we realize that the details of our classification are not completely consistent. Even the giants in the field disagree on some points, and one of those points is in the breakdown of the Facelinidae and Glaucidae families. One school of thought keeps these families separate, and maintains a number of different genera under Facelinidae. The other places both families under Glaucidae and synonymizes a number of genera under Phidiana. We show a combination of these two viewpoints, but not from any real conviction about what is correct. Rather, we have organized things this way simply out of convenience. No doubt as time goes on and we have time to think about the issue further, we will migrate towards one view or the other.
If you find the thumbnails too slow to load, this link will take you to the same list of links without thumbnails.
FLABELLINIDAE
Flabellina
bicolor
Flabellina
bilas
Flabellina
delicata
Flabellina
exoptata
Flabellina
riwo
Flabellina
rubropurpurata
Flabellina
sp. e094
Flabellina
sp. e625
Flabellina
sp. e626
Flabellina
? sp. e639
PISEINOTECIDAE
Piseinotecus
sp. e332
EUBRANCHIDAE
Eubranchus
mandapamensis
Eubranchus
sp. e133
Eubranchus
? sp. e271
Eubranchus
? sp. e315
Eubranchus
sp. e611
Eubranchus
? sp. e613
AEOLIDIIDAE
Aeolidiella
alba
Baeolidia
japonica
Baeolidia
nodosa
Baeolidia
sp. e249
Baeolidia
sp. e320
Baeolidia
sp. e614
Berghia
major
Berghia
sp. e627
Cerberilla
annulata
Cerberilla
sp. e643
Protaeolidiella
juliae
GLAUCIDAE
Glaucus
atlanticus
FACELINIDAE
Caloria
? sp. e521
Caloria
sp. e562
Cratena
cf affinis
Cratena
? sp. e430
Cratena
sp. e591
Cratena
sp. e640
Facelina
bourailli
Favorinus
japonicus
Favorinus
mirabilis
Favorinus
? sp. e428
Favorinus
sp e554
Favorinus
sp. e574
Godiva
sp. e032
Herviella
albida
Noumeaella
rehderi
Noumeaella
sp. e220
Noumeaella
? sp. e242
Phidiana
indica
Phidiana
sp. e551
Phidiana
? sp. e390
Phyllodesmium
hyalinum
Phyllodesmium
magnum
Phyllodesmium
sp. e426
Phyllodesmium
sp. e617
Pruvotfolia
rhodopos
Pruvotfolia
? sp. e313
Pruvotfolia
? sp. e499
Pteraeolidia
ianthina
Babakina
indopacifica
TERGIPEDIDAE
Cuthona
acinosa
Cuthona
cf diversicolor
Cuthona
poritophages
Cuthona
sibogae
Cuthona
? sp. e128
Cuthona
? sp. e238
Cuthona
sp. e272
Cuthona
sp. e282
Cuthona
sp. e293
Cuthona
sp. e329
Cuthona
? sp. e171
Cuthona
sp. e427
Cuthona
sp. e432
Cuthona
sp. e498
Cuthona
? sp. e505
Cuthona
sp. e595
Cuthona
sp. e603
Cuthona
sp. e612
Cuthona
sp. e637
Cuthona?
sp. e649
Cuthona?
sp. e650
Phestilla
lugubris
Phestilla
minor
Phestilla
sp. e657
Family UNKNOWN
eolid
sp. e308
eolid
sp. e314
eolid
sp. e330
eolid
sp. e429
eolid
sp. e431
eolid
sp. e652
