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Species index
Species index
©2010 Emerald Diving
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Freckled Pale Sea Lemon
Peltodoris lentiginosa
Typical size: 6-10” length
ID: Dorid shape.  Large pale yellow body with large dark and light brown patches. Small to medium sized tubercles cover entire body.  Thick branchial plume on rear.
Comments:  This is one of the largest nudibranch species in Washington waters.  I often note this nudibrach in the San Juan Islands and Hood Canal on rocky substrates.  The density of the brown patching varies greatly.
Sea Lemon Dorid
Peltodoris nobilis
Typical size: 3-8” length
ID: Yellow or pale yellow dorid shaped body.  Branchial plume is white.  Body covered with flat yellow tubercles.  Dark patches on body do not extend to tubercles.
Comments: I note sea lemon dorids more than any other nudibranch in our state.  Sea lemon dorids can grow quite large and be almost as wide as they are long.  The reef on the east side of Blakely Rock is a great place to find large specimens.



Shaggy Mouse Nudibranch
Aeolidia papillosa
Typical size: 1-3” length
ID: Two distinct rows of dense cerata.  White/crθme colored body, often with purple or grey on top (but not always).  Cerata start in front of rhinophores.
Comments:  I rarely note the well camouflaged shaggy mouse nudibranch. When I do note this species, it is typically on a rock or attached to eel-grass.  I have had my best luck finding this species at KVI Tower Reef in Puget Sound, which is where I found this specimen.

Spotted Aglajid
Aglaja ocelligera

Typical size: 1-2”  length
ID: Elongated, smooth, and rounded dark body with small white and/or yellow spots.
Comments:  I only note the spotted aglajid on soft substrates when broadleaf kelp is present.  The soft substrate above the reef at KVI Tower seems to be a favorite location for this nudibranch, at least during summer months when high concentrations of kelp are present.

Variable Nudibranch
Dendronotus diversicolor
Typical size: 2-4” length
ID:  Translucent white or lilac elongated  body.  Four rows of gill tufts tipped with white and/or orange.  White stripe runs from the last gill tuft to the tail.  
Comments: I usually note the beautiful variable nudibranch in Puget Sound and the San Juan Islands feeding on hydroids.  White variations are easily mistaken for white dentronotids.  Note the short white stripe that only runs from the last gill tuft to the tail.  Photo taken at Long Island in the San Juan Islands.



White Dendronotid
Dendronotus albus
Typical size: 2-4” length
ID:  Elongated, translucent white body.  Up to seven sets of gill tufts tipped with white and/or orange.  White stripe runs from the fourth pair of gill tufts to the tail. 
Comments:
I most often note the white dendronotid clinging to hydroids in the San Juan Island area.  I rarely note the white dentronotid outside of the San Juan Islands.


Verrucose Aeolid
Flabellina verrucosa
Typical size: 2-4” length
ID:  Red cerata tipped in white arranged in several clumps on either side of the body.  Long smooth rhinophores. 
Comments: 
I rarely note this species of nudibranch.  This species looks like a red flabillina with a bad haircut, as the red flabillinas cerata are more even.  Diet consists of hydroids and possibly other invertebrates.   


Yellow Margin Nudibranch
Cadlina luteomarginata
Typical size: 2-3” length
ID: White body covered with prominent white tubercles tipped in yellow. Yellow margin around foot. White branchial plume.
Comments:  I often note this species throughout Washington water on soft and hard substrates.  Compared to most other nudibranch, the yellow margin nudibranch maintains a very flat profile.  Possession Poinf Fingers are a great place to find observe the yellow margin nudibranch.  This is another species that is quick to retract its branchial plume when approached.


Striped Nudibranch
Armina californica
Typical size: 3-6”  length
ID: Elongated brown body with horizontal white stripes.  White margin around foot.  Club-like rhinophores.
Comments:  I often note this nudibranch in sandy areas with dense seapen congregations, which just happen to be this nudibranchs favorite food.  I have consistently noted this species on the northern section of the shelf above Possession Point Fingers.  Once the striped nudibranch finds a seapen to devour, it will often dig in the sand to attack the subterranean base of soft coral.

Red Nudibranch
Dendronotus rufus
Typical size: 4-10” length
ID: White elongated body.  Purple to red tipped branching cerata.
Comments:   I rarely note red nudibranchs.  My best luck for sighting this spectacular species is at Possession Point Fingers during summer months where I sometimes find these nudibranchs patrolling the underside of ledges.  The specimen was found in Blakely Harbor  patrolling an old wooden wreck.


Red Flabellina
Flabellina fusca
Typical size: 2-3” length
ID: Dense rows of red and/or pink cerata tipped in white on either side of body.  Relatively short rhinophores have very subtle ridges.
Comments: I only occasionally note the red flabellina on soft substrates.  I have encountered high concentrations of this species during summer months at Flagpole Point in Hood Canal on the soft substrate above the rocky wall, which is where this image was taken.


San Diego Dorid
Diaulula sandiegensis
Typical size: 2-4” length
ID: Dorid shaped smooth white body with small black  patches or loops. White branchial plume.
Comments: I often note the San Diege dorid on hard and soft substrates.  This nudibranch often sports dark rings on its back rather than patched.  San Diego dorids often patrol the vegetation along the guide lines throughout Edmonds Underwater Park.  This species is also referred to as a leopard nudibranch.


Red Flabellina

Red Flabellina

Red Nudibranch

Red Nudibranch

San Diego Dorid

San Diego Dorid

Sea Lemon Nudibranch

Sea Lemon Nudibranch

Shaggy Mouse Nudibranch

Shaggy Mouse Nudibranch

Spotted Aglajid

Spotted Aglajid

Striped Nudibranch

Striped Nudibranch

Variable Nudibranch

Variable Nudibranch

Verrucose Aeolid

Verrucose Aeolid

White Dendronotid

White Dendronotid

White Lined Dirona

White Lined Dirona

Yellow Margin Dorid

Yellow Margin Dorid

Shaggy Mouse Nudibranch
Aeolidia papillosa
Typical size: 1-3” length
ID: Two distinct rows of dense cerata.  White/crθme colored body, often with purple or grey on top (but not always).  Cerata start in front of rhinophores.
Comments:  Note how different this example of a shaggy mouse nudibranch is compared to the one above, showing how different physical characteristics can be even within the same species.  I found this and dozens of similar nudibranchs feeding on anemones at KVI Tower Reef in 9 feet of water.

Shaggy Mouse Nudibranch

Shaggy Mouse Nudibranch

White Lined Dirona
Dirona albolineata
Typical size: 2-5” length
ID: Semi-translucent white or lavender colored body with triangular shaped cerata edged in bright white.
Comments:  This amazing looking nudibranch is commonly sighted by divers in Northwest waters.  It seems at home on soft and hard substrates.  Although typically predominately white, this nudibranchs diet can effect body color.  Photograph taken at Three Tree Point in Central Puget Sound.
Bi-colored Nudibranch
Janolus fuscus
Typical size: 1-2” length
ID: Translucent white body. Densely packed pointed cerata with maroon center and tipped with yellow and white. 
Comments:
  I typically note these picturesque nudibranchs on broadleaf kelp around soft substrates.   Note the orange stripe on this species head.  I regularly find large specimens at Three Tree Point in spring on broadleaf kelp from shallow depths to over 90 feet deep.

Cockerell’s Dorid
Laila cockerelli
Typical size: 0.75-1” length
ID: White body. Dorid shape with distinctive orange tipped papilla.  Rhinophores tipped in red.  
Comments: I rarely note the tiny Cockerell's dorid, most likely because of its small size and the fact it is well camouflaged when amongst other colorful invertebrates. Most of my sightings are in the San Juan Islands on current swept rocky reefs amongst thick invertebrate populations.  This photography was taken at Strawberry Island in the San Juan Islands.

Dall’s Dendronotid
Dendronotus dalli
Typical size: 3-5” length
ID: White or pinkish-white body with six or seven rows of white tipped gill tufts that are heavily branched and tipped in bright white.
Comments:  I usually note this nudibranch around invertebrate rich rocky reef areas in the San Juan Islands.  This species is easily confused with the white dendronotid.  Photo taken at Long Island in the San Juan Islands.
Giant White Dorid
Doris odhneri
Typical size
: 2-8” length
Distinctive markings:  Dorid shaped white body with no color markings.  Medium sized tubercles over entire body.  White rhinophores and branchial plume on rear.
Comments:  I frequently note this nudibranch in large numbers at certain sites in the San Juan Islands. This picture was taken at Lawrence Point on Orcas Island.  I have noted this species in a pale yellow color in the Hood Canal area.

Hudson Dorid
Acanthodoris hudsoni
Typical size: 1-2” length
ID:  White dorid shaped body covered in small white papillae tipped with yellow. Yellow margin. Long, prominent rhinophores.  Rhinophores and gill plume are white.
Comments:  A very common species that I have noted throughout all Washington waters around rocky reef areas and broadleaf kelp beds.  it is often confused with the Nainimo dorid which boasts rust colored rhinophores and branchial plume.

Golden Dirona
Dirona aurantia
Typical size: 2-8” length
Distinctive markings:  Dorid shaped white body with no color markings.  Medium sized tubercles over entire body.  White rhinophores and branchial plume on rear.
Comments:  I frequently note this nudibranch in large numbers at certain sites in the San Juan Islands. This picture was taken at Lawrence Point on Orcas Island.  I have noted this species in a pale yellow color in the Hood Canal area.

Lion Nudibranch
Melibe leonina
Typical size: 3-8” length
ID: Translucent white or yellowish brown body, sometimes with white spots.  Large frontal hood that can be extended to trap food drifting in the current.  Cerata are disk shaped. 
Comments: I only note the lion nudibranch in summer and fall amidst eel-grass and broadleaf kelp beds at depths above 40 fsw.  This species swims by undulating its body as it drifts in the current.   Also referred to as a hooded nudibranch.

Monterey Dorid
Doris montereyensis
Typical size:  2-6” length
ID: Dorid shaped yellow body.  Yellow branchial plume and rhinophores.  Black spots on body that can extend onto tubercles.
Comments:  I commonly note this nudibranch on soft substrates.  This species is easily mistaken for a sea lemon nudibranch (Anisodoris nobilis) which has a white branchial plume and is usually a paler yellow.  I often find this species with sand on its dorsum.

Nanaimo Dorid
Acanthodoris nanaimoensis
Typical size: 1-3” length
Distinctive markings: White dorid shaped body covered with small papillae tipped in yellow. Branchial plume and rhinophores tipped in rust.
Comments: I commonly note the Nanaimo dorid around rocky reef areas.  This nudibranch is often mistaken for a Hudson's dorid which lacks the rust coloration on the rhinophores are branchial plume.  Nanaimo dorids are believed to primarily feed on bryozoans and ascidians.


Opalescent Nudibranch
Hermissenda crassicornis
Typical size: 0.5-3” length
ID: Densely packed long, narrow cerata tipped in orange.  Distinctive orange stripe on head.  Body color varies from light blue to white.
Comments:
One of the most picturesque of the nudibranch species in northwest waters.  I usually note very small specimens in our waters (less than 1 inch). The amount of orange color on the cerata can vary greatly.   This nudibranch feeds on hydroid, ascidians, and other invertebrates.


Orange Spotted Nudibranch
Triopha catalinae
Typical size: 3-8”  length
ID: Elongaged white body with orange tipped gill tufts and rhinophores.
Comments: 
One of the most common nudibranch species  encountered when diving rocky reefs.  This robust nudibranch is also sometimes referred to as a clown nudibranch.   This species is reported to feed on various bryozoans.  Photo taken at Pile Point on the south side of San Juan Island.

Orange Peel Nudibranch
Tochuina tetraquerta
Typical size: 6-10” length
ID: Thick orange body with white margin and large tubercles tipped in white.  White "fringe"(gills) lines the top of the body. 
Comments: This nudibranch is one of the largest and most distincitive in Washington waters.  Unfortunately, it is also one of the rarest.  I only occasionally note this species in the Cape Flattery area on rocky reefs where sea strawberries (a favorite prey item) are present.  Photographed at Tatoosh Canyon near Cape Flattery.


Freckled Pale Sea Lemon

Freckled Pale Sea Lemon

Bicolored Nudibranch

Bicolored Nudibranch

Cockerell's Dorid

Cockerell's Dorid

Hudson Dorid

Hudson Dorid

Dall's Dendronotid

Dall's Dendronotid

Giant White Dorid

Giant White Dorid

Golden Dirona

Golden Dirona

Lion Nudibranch

Lion Nudibranch

Monterey Dorid

Monterey Dorid

Nanaimo Dorid

Nanaimo Dorid

Opalescent Nudibranch

Opalescent Nudibranch

Orange Peel Nudibranch

Orange Peel Nudibranch

Orange Spotted Nudibranch

Orange Spotted Nudibranch

Diamond Back Nudibranch

Diamond Back Nudibranch

Diamond Back Nudibranch
Tritonia festiva
Typical size: 2-5” length
ID: Elongated translucent white body.  Prominent  frontal veil.  Gill tufts aligned in rows along side of body. 
Comments: I often note this nudibranch in rocky reef areas and soft substrates. The diamond pattern on the back of this nudibranch can be very faint or even non-existent.  This photograph was taken at south Lopez Island. However, I often find this species amongst the orange seapens above the wall at Possession Point.  Also referred to as a festive nudibranch. 

Click here for nudibranch related terms and facts
Heath's Dorid
Geitordoris heathi
Typical size: 23” length
Distinctive markings:  White or yellow dorid shaped body with tiny yellow brown or black specs.  Branchial plume on rear.
Comments:  I rarely note this nudibranch.  I found this specimen at Cone Island in the San Juan Islands - an invertebrate Mecca.

Heaths Dorid

Heaths Dorid

Cooper’s Dorid
Aldisa cooperi
Typical size: 1-1.5” length
ID: Solid yellow-orange body with small black spots on the centerline of the dorsum.  
Comments: I only note this species when diving the Cape Flattery area.  The branchial plume of the animal on the left is retracted.  The Cooper's dorid is usually found around encrusting sponges, which it dines upon.  Photo taken at Tatoosh Canyon in the Cape Flattery area.

Coopers Dorid

Coopers Dorid

Pilose Doris
Acanthodoris pilosa
Typical size: 1-2”  length
ID: Small triangular papillae.  Long rhinophores that bend slightly  backwards.  White body.
Comments: 
I believe this is a pilose doris.  I have only noted this nudibranch once, and that was while diving Tatoosh Canyon in the Cape Flattery area.  This nudibranch is usually only about an inch in len
gth, but this specimens was closer to  two inches. 
Pilose Doris

Pilose Doris

Bushy-Back Nudibranch
Dendonotus frondosus
Typical size: 1” length
ID: Dendrontid shape with defined spiral rhinophore tips.  Usually brown in color.
Comments:  This is a difficult little nudibranch to find.  It looks just like the hydroids it feeds on and is very hard to spot unless you are looking for it.  These nudibranchs are readily found grazing on hydroids on broadleaf kelp at Three Tree Point during summer, which is where this photo was taken. 
Bushy-Backed Nudibranch

Bushy-Backed Nudibranch

Giant Nudibranch

Giant Nudibranch

Giant Nudibranch
Dendronotus iris
Typical size: 4-10” length
ID: White or red dendronotid body with long, branching gill tufts. Large size
Comments: This large nudibranch specializes in hunting tube-dwelling anemones.  When an anemone is found, this nudibranch rears up and dives in the middle of the anemone - it is quite spectacular.  The giant nudibranch is also palagic - it can swi my undulating it's body.  Photo taken at Pulali Wall in Hood Canal.

California Berthella
Berthella californica
Typical size: 2-3” length
ID: White or orange rounded body with speckles.  No branchial plume.  Highlighted margin.  Two tubular shaped rhinophores. 
Comments: This is another nudibranch that I just don't note often in Washington waters.  I occasionally see this spiecies in Hood Canal and the Cape Flattery area.  This photo was taken at Third Beach Pinnacle near Neah Bay.  I apologize for the poor quality - I had to light this shot with my HID light as my camera flash was inoperable.

California Berthella

California Berthella

Giant Nudibranch Juvenile

Giant Nudibranch Juvenile

Giant Nudibranch - Juvenile
Dendronotus iris
Typical size: 2-3” length
ID: White or red dendronotid body with long, branching gill tufts. Large size
Comments: I have only once noted a juvenile Dendronotus iris.  The photograph was taken near the public beach access at Three Tree Point in 15 feet of water.  Ironically, I have never seen an adult version of this nudibranch at this site.   Note the tri-colored gill tufts.

Pink Nudibranch
Tritonia diomedia
Typical size: 5-8”  length
ID: Thick, pink, "square" body with frontal veil trimmed in white.  White fringe (gills) along top edges of body.
Comments: 
I only rarely find this species.  When I do find pink nudibranchs, it is always amidst orange seapens on sandy substrates.  My understanding is that this species was harvested in our area for brain research.  Sadly, not many of this impressive species exists in our waters anymore.
  Photographed at Alki Reef in Central Puget Sound.  Note the orange seapen.
Pink Nudibranch

Pink Nudibranch

Bushy-Back Nudibranch
Dendonotus frondosus
Typical size: 3” length
ID: Dendrontid shape with defined spiral rhinophore tips.  Usually brown in color.
Comments:  This specimen was photographed in Quatsino located on NW Vancouver Island.  The specimen is much bigger and sports much more white than the species normally found in the Puget Sound region (see above).  
Bushy-Backed Nudibranch

Bushy-Backed Nudibranch

Pomegranate Nudibranch

Pomegranate Nudibranch

Pomegranate Aeolid
Cuthona punicea
Typical size: 1”  length
ID: Smooth rhinophores, lavender coloration to rhinophores with white markings.
Comments: 
This tiny nudibranch is exclusively associated with raspberry hydroids, which are currently only known to exist in the northeast Vancouver Island area.  Photograph taken near Pearse Island in the Johnstone Strait.

Three Lined Aeolid

Three Lined Aeolid

Three Lined Aeolid
Flabellina trilineata
Typical size: 2”  length
ID: Three white lines run along the top of the body.  Red-colored cerate concentrated in isolated clumps.
Comments:  A rarely noted nudibranch that looks very similar to several others, including the red flabellina and verrucose aeolid.  I had to go to Browning Pass to find this specimen cruising the colorful invertebrates.

Modest Cadlina

Modest Cadlina

Modest Cadlina
Cadlina modesta
Typical size: up to 1.75” length
ID: Dorid shape, distinctive bright spots (yellowish-white) along margin that extend to rhinophores. 
Comments: I rarely note this tiny nudibranch as i am sure I mistaken it for a juvenile of several other similar species. However, the row of bright plae yellow spots long the margin are somewhat distinctive.  Photographed at Long Island west wall, just south of Lopez Island.