male holding female

Cancer gracilis Dana, 1852
Graceful Crab
intertidal to 175m carapace to 115mm wide
north Mexico to central Alaska
Similar in appearance to Dungeness crab, this one has a white margin around the carapace and is widest at the 9th tooth, walking legs are purplish in color in adults

Caprellidae

Caprella sp.
Skeleton Shrimp
intertidal to subtidal size to 4cm
common, central California to north Alaska
Stick-like bodies, several species present in our area

found in a Tresus capax siphon
Pinnixa littoralis Holmes, 1894
Gaper Pea Crab
intertidal to 91m carapace to 27mm wide
north Mexico to central Alaska
White and sometimes with dark markings, also frequently found in Tresus capax and other clams

Balanus rostratus Hoek, 1883
Rostrate Barnacle
low intertidal to 338m
size to 5.6 cm wide
Washington to north Alaska, Japan
Usually smooth with a narrow top, one side more vertical than the other

Balanus glandula Darwin, 1854
Common Acorn Barnacle
intertidal size to 2.2cm wide
north Mexico to north Alaska
Our most common intertidal barnacle, ridged outer plates, inner plates form a sinuous "W" or "M" shape, in crowded conditions can become elongated

Balanidae

Balanus crenatus Bruguière, 1789
Crenate Barnacle
intertidal to 182m size to 2cm wide
common, south California to north Alaska
Smooth white plates, squat appearance with wide base, usually attached to smooth surfaces, inner plates form a sharp "W" or "M" shape

Chthamalidae

Chthamalus dalli Pilsbryi, 1916
Small Acorn Barnacle
intertidal south California to north Alaska size to 6mm wide
Gray-brown color, inner plates form a cross pattern

Balanus nubilus Darwin, 1854
Giant Acorn Barnacle
intertidal to 90m Size to 15 cm wide
north Mexico to south Alaska
A very large barnacle

Archaeobalanidae

Semibalanus cariosus (Pallas, 1788)
Thatched Acorn Barnacle
intertidal to 54m size to 6cm wide
south California to north Alaska, Japan
Walls with numerous fine ridges that form into downward pointing spines

Crustaceans

(Oregon to Southeast Alaska)

Click on photo to enlarge. Scale line in photo equals 1cm unless otherwise specified.

adult male holding female juveniles are variable in color and pattern

Cancer productus Randall, 1840
Red Rock Crab
intertidal to 79m north Mexico to central Alaska carapace to 200mm wide
Adults are solid red, juveniles are variable in color including striped patterns, strong claws with black tips

Pollicipedidae

Pollicipes polymerus (Sowerby, 1833)
Goose-Neck or Leaf Barnacle
intertidal to 30m size to 15cm high
north Mexico to south Alaska
Numerous plates cover the barnacle, lives in areas of strong waves or high currents

Hemigrapsus oregonensis (Dana, 1851)
Green Shore Crab
intertidal (to shallow subtidal in some spots) north Mexico to south Alaska carapace to 2cm wide
Abundant, usually greenish but may be red to purple, juveniles can be variable in color, fringe hairs along the walking legs, a slight notch in the carapace between the eyes

Grapsidae

Hemigrapsus nudus (Dana, 1851)
Purple Shore Crab
high to mid intertidal north Mexico to south Alaska carapace to 5cm wide
Very common, usually reddish-purple but can be green, sometimes claws have dark reddish spots, juveniles can be variable in color including all white, no hair on the walking legs

Epialtidae

Pugettia gracilis Dana, 1851
Graceful Kelp Crab
intertidal to 367m north Mexico to north Alaska carapace to 45mm wide
Usually red but juveniles variable from white to red, may decorate with a single piece of seaweed on its long rostrum

Oregoniidae

Oregonia gracilis Dana, 1851
Graceful Decorator Crab
intertidal to 436m central California to north Alaska, Japan carapace to 39mm wide

Cancer oregonensis (Dana, 1852)
Pygmy Rock Crab
intertidal to 435m north California to central Alaska carapace to 50mm wide
Brownish red to orange to white, rounded carapace with warty protrusions, hairy legs, claw tips are black, found under rocks or in empty giant barnacle shells

Lepadidae

Lepas anatifera Linnaeus, 1758
Pelagic Goose-Neck Barnacle
pelagic size to 20 cm long
South America to Alaska
lives at sea attached to flotsam, especially driftwood, often found washed ashore

Talitridae

Traskorchestia traskiana (Stimpson, 1857)
Pacific Beach Hopper
very high intertidal size to 2cm
north Mexico to north Alaska
Gray to red-brown, found in the high beach drift, one of many similar species on our beaches

Hyalidae

Beach Hopper
unidentified
mid to high intertidal - Many similar looking species present on our beaches

Ampithoidae

Ampithoe sp.
Sea Fleas
intertidal to subtidal north Mexico to Alaska size to at least 2.5cm
These tend to be lower intertidal or subtidal. The individual species can really only be determined by dissection.

Sphaeromatidae

Exosphaeroma russellhansoni
Wall, Bruce & Wetzer, 2015
intertidal Washington 8.6mm
This species was separated from
E. amplicauda.

Ligiidae

Ligia pallasii Brandt, 1833
Sea Slater
Very high intertidal size to 3.7cm
central California to north Alaska
Gray brown to slate gray, only found in the high splash zone

Gnorimosphaeroma oregonense (Dana, 1853)

Oregon Pill Bug
intertidal central California to Alaska size to 1cm
Black to gray to tan, can roll up into a ball to protect itself

Pinnotheridae

found inside a Tresus capax

Pinnixa faba (Dana, 1851)
Mantle Pea Crab
intertidal to subtidal carapace to 25mm wide
south California to south Alaska
Usually orange but sometimes white or mottled, often found living inside Tresus capax but never T. nuttallii, can also be found inside other clams and a few mollusks and sea cucumbers

Panopeidae

a female brooding its eggs

Lophopanopeus bellus (Stimpson, 1860)
Black-Clawed Crab
intertidal to 80m south California to south Alaska carapace to 40.5mm wide
Variable in color, fingers of claw almost always very dark

Cheiragonidae

male holding female

Telmessus cheiragonus (Tilesius, 1812)
Helmet Crab
intertidal to 180m central California to north Alaska; Siberia, Japan & Korea carapace to 102mm wide
Typically yellowish-green, sometimes reddish, covered with bristly hairs

Pugettia producta (Randall, 1840)
Northern Kelp Crab
intertidal to 73m carapace to 110mm wide
north Mexico to south Alaska
Kelp brown to dark red with smooth carapace, only juveniles seem to decorate rostrum with a piece of seaweed

Pentidotea wosnesenskii (Brandt, 1851)
Rockweed Isopod
intertidal to 16m size to 4cm
north Mexico to central Alaska & Sea of Okhotsk
May be black, shades of brown, greens or red, tail segment is rounded with a very slight point at the end

Pleustidae

Chromopleustes oculatus (Holmes, 1908)
Black and White Sea Flea
intertidal to at least 12m size to 1cm
central California to BC
Black with gold stripes and a white midsection, lives in areas with strong currents

Sunamphitoe sp. (previously Peramphithoe)
Sea Flea
intertidal to ~18m size to at least 5cm
north Mexico to south Alaska
Pictured species is likely S. humeralis which is found around brown kelp

juvenile
Echidnocerus cibarius White, 1842
Puget Sound King Crab
subtidal to 137m carapace to 308mm wide
central California to south Alaska
Red with yellow, orange & purple markings, juveniles have pronounced elevations on the carapace
This is a protected species.

Orthione griffenis Markham, 2004
Upogebia Gill Isopod
intertidal size to 1cm
north Mexico to BC, introduced from Asia
This is a parasite of the Blue Mud Shrimp. The male and female of this isopod have different appearances. It is an invasive species.

Pinnixa comparison
These are two male Pinnixa.
Note that the longest segment
of the third walking leg of the male is fatter on the P. littoralis than on P. faba.

Idoteidae

Pentidotea resecata (Stimpson, 1857)
Eelgrass Isopod
intertidal to 19m size to 4cm
north Mexico to central Alaska
Yellow-brown or green, tail segmented looks forked

in a Neptunea lyrata in a Fusitriton oregonensis

Elassochirus tenuimanus (Dana, 1851)
Widehand Hermit
intertidal to 388m carapace to 50mm long
north Washington to north Alaska
Reddish brown with purple-blue on the upper part of the walking legs, right claw is large and flattened

Pachycheles rudis Stimpson, 1859
Thickclaw Porcelain Crab
intertidal to 29m carapace to 19mm wide
north Mexico to central Alaska
Color variable and often mottled gray, brown or white, large claws are unequal in size

Phyllolithodes papillosus Brandt, 1848
Heart Crab
extreme low tide to 183m south California to central Alaska carapace to 100mm
Gray to brown, juveniles white with orange or purple markings, triangular carapace with heart-shaped sculpturing, walking legs have white bands, legs and claws covered with blunt flattened projections

Cryptolithodes typicus Brandt, 1848
Butterfly Crab
intertidal to 55m caparace to 80mm wide
south California to central Alaska
Variable in color, carapace has more angular outline than C. sitchensis and bumps on its claws

in a Nucella lamellosa in a Nucella lamellosa using a Hairy Hermit crab claw for a shell without a shell

Pagurus granosimanus (Stimpson, 1858)
Grainyhand Hermit Crab
intertidal to 36m northern Mexico to central Alaska carapace to 19mm long
Olive green with blue granules, orange or red antennae, claws have a granular appearance, prefers shells which seem too large so it can completely withdraw inside

Pentidotea stenops
(Benedict, 1898)
Feather Boa Isopod
intertidal - subtidal size to 4cm
north Mexico to south Alaska
Brown, narrows at tail end which is rounded with a small point

in a Ceratostoma foliatum juvenile in a Haminoea vesicula juvenile in a Nucella ostrina

Pagurus hirsutiusculus (Dana, 1851)
Hairy Hermit
intertidal south California to north Alaska carapace to 31.7mm long
Variably colored, becoming more olive green with age, banded antennae, hairs on legs and claws, hairiness can be variable, blue dot at dactyl of walking leg, juveniles have white bands on legs and claws, prefers shells on the small side, extremely common on Pacific Northwest beaches

in a Lacuna vincta in a Littorina scutulata

Pagurus holmi Ng & McLaughlin, 2009
intertidal size to 3mm
currently known only from the south Salish Sea
This tiny species was discovered by members of the PNWSC during a field trip in May 2008. Nearly identical to a very juvenile Hairy Hermit but is an adult at this size. The walking legs lack the blue dot on the Hairy Hermit.

in a Neverita lewisii

Pagurus armatus (Dana, 1851)
Blackeyed Hermit
intertidal to 185m carapace to 50mm long
south California to north Alaska
Reddish orange and white bands on legs, erect black eyes, a line of spines down middle of legs

juvenile found at very low tide in Alaska
Paralithodes camtschaticus
(Tilesius, 1815)
Red King Crab or Alaska King Crab
subtidal, north BC to north Alaska,
Japan & Siberia

Hapalogastridae

Oedignathus inermis (Stimpson, 1860)
Granular Claw Crab
intertidal to 50m carapace to 25mm
central California to central Alaska; Japan, Korea and Siberia
Brown to bluish, right claw much larger and covered in warty blue granules, frequently in rock crevisses and holes and prefers the outer coast or other high current locations

Thoridae

Heptacarpus brevirostris (Dana, 1852)
Stout Shrimp
intertidal to 128m south California to north Alaska size to 62mm
Color and pattern extremely variable, short rostrum ends in a single point, one of most frequently seen shrimp in the intertidal

Grapsidae

Pachygrapsus crassipes Randall, 1840
Striped Shore Crab
intertidal north Mexico to south BC carapace to 48mm wide
Striped pattern, red-black with green
Caution - readily pinches when handled

in a Nucella canaliculata
Elassochirus gilli (Benedict, 1892)
Pacific Red Hermit
intertidal to 200m carapace to 38mm long
north Washington to north Alaska
Brilliant red or orange claws and legs, white carapace

female with eggs

Crangon nigricauda Stimpson, 1856
Blacktail Shrimp
intertidal to 201m north Mexico to central Alaska size to 68mm
A common intertidal Crangon, tail sometimes but not always black

Scyra acutifrons Dana, 1851
Sharpnose Crab
intertidal to 220m carapace to 45mm
north Mexico to Alaska
Brown to tan but frequently encrusted, surface of carapace very irregular, rostrum is two flattened leaf-like horns with rounded outside edges

Cancer magister Dana, 1852
Dungeness Crab
intertidal to 230m south California to north Alaska carapace to 254mm wide
Similar in appearance to Graceful crab, carapace widest at 10th tooth, serrated along edge of claws, juveniles are variable in color, grows much larger than the Graceful crab

Cancer antennarius Stimpson, 1856
Pacific Rock Crab
intertidal to 90m carapace to 178mm wide
north Mexico to north BC
Common on the exposed coast, reddish-brown with strongly curved spines along carapace margin, black-fingered claws

Carcinus maenas (Linnaeus, 1758)
European Green Crab
intertidal to~ 6m (deeper in its native region) carapace to 100mm wide
central California to south BC, introduced from Europe
Highly invasive, mottled green and yellow, juveniles variable in color and pattern, differs from all other west coast crabs with its 5 teeth on each side of carapace, so far has only isolated populations on west coast primarily in high intertidal salt marshes

Emerita analoga (Stimpson, 1857)
Pacific Sand Crab
intertidal carapace to 33mm long
north Mexico to central Alaska
Gray, egg-shaped body, found on wave-swept sandy beaches

Paguridae

Discorsopagurus schmitti (Stevens, 1925)
Tubeworm Hermit
intertidal to 220m size to 7mm
south Oregon to south Alaska
Reddish-brown bands on legs, yellow or orange claw fingers, lives in calcareous tubeworm shells which are attached to rocks

in a Nucella lamellosa in a Ceratostoma foliatum

Pagurus beringanus (Benedict, 1892)
Bering Hermit
intertidal to 364m carapace to 26mm long
central California to north Alaska
Pale blue walking legs with red spots and bands, reddish spiny claws, prefers a large heavy shell

in a Nucella lamellosa
Pagurus kennerlyi (Stimpson, 1864)
Bluespine Hermit
intertidal to 274m carapace to 35mm long
north Washington to north Alaska; Japan
Pale blue to white claws covered with spines, walking legs have reddish-brown blotches, banded antennae

Placetron wosnessenskii schalfeew, 1892
Scaled Crab
Subtidal to 185m carapace to 73.3mm wide
north Washington to central Alaska
Very rarely intertidal, greenish-gray to reddish, carapace and legs covered in scale-like plates

Porcellanidae

Pachycheles pubescens Holmes 1900
Pubescent Porcelain Crab
intertidal to 55m carapace to 22mm
north Mexico to north BC
Color reddish-brown to orange-brown, claws covered with short thick brown hair, rostrum is hairy and pointed

Petrolisthes cinctipes (Randall, 1840)
Flat Porcelain Crab
intertidal carapace to 24mm
south California to north BC
Light to dark brown color, carpus of claw very broad, high to mid intertidal on or near the outer coast

Cryptolithodes sitchensis Brandt, 1853
Umbrella Crab
intertidal to 37m south California to south Alaska carapace to 90mm wide
Bright red to orange, gray or white, sometimes with patterns, smooth claws, more rounded outline than C. typicus

Rhinolithodes wosnessenskii Brandt, 1848
Rhinoceros Crab
subtidal to 201m carapace to 74mm
north California to central Alaska
Gray-brown with orange and cream markings, triangular carapace with a deep semicircular depression, legs and claws covered with spines tipped with long hairs

Lebbeus grandimanus (Brazhnikov, 1907)
Candy-stripe Shrimp
subtidal to 250m size to 45mm
north Washington to central Alaska; Russia & Japan
Bright bands of red, yellow and blue; lives in association with anemones

Pandalus danae Stimpson, 1857
Dock Shrimp
intertidal to 263m south California to Alaska size to 140m
Variable in color depending on habitat, broken diagonal stripes on body, often has bright blue spots, legs and antennae are banded

Petrolisthes eriomerus Stimpson, 1871
Flattop Crab
intertidal to 86m south California to south Alaska carapace to 19mm wide
Dark brown to blue, blue spot at base of the moveable finger of the claw