crabs
blackeye hermit crab
Scientific name: Pagurus armatus
Family: Paguridae
Phylum: Arthropoda
Typical size: 4.5 centimeters
Depth range: 0 to 150 meters
Description: As the name suggests, this hermit crab has black eyes. Their body and pinchers are an orangish-red color. Its arms have white and brown lines and splotches on them. They have a curved abdomen that will help it hold onto the inside of the shell it is living in.
Habitat and behavior: Lives from Northern Alaska to southern California. They usually live on sand, mud or gravel seafloors scavenging for food.
dungeness crab
Scientific name: Metacarcinus/Cancer magister
Family: Canceridae
Phylum: Arthropoda
Typical size: 12 to 20 centimeter carapace width
Depth range: 5 to 35 meters
Description: Their shell is brownish-purple in color, only with spine tips along the front part of the shell. The carapace is smooth and lacks detail other than vaguely heart-shaped markings in the center of the shell. Dungeness crabs have large claws and relatively short legs compared to the size of their carapace. Their claws have small teeth that help to break open hard shells and hold food.
Habitat and behavior: They thrive in cold waters around eelgrass beds or sand flats. They break muscles and other bivalves, and oftentimes are flocked by scavengers such as ratfish and other fish when eating.
graceful decorator crab
Scientific name: Oregonia gracilis
Family: Majidae
Phylum: Arthropoda
Typical size: Carapace length reaches 5 centimeters
Depth range: Intertidal to 436 meters
Description: Heart shaped body with two spine-like processes protruding from head. Curved spines behind the eyes help distinguish this species from the longhorn decorator crab (Chorilia longipes). Pinchers (chelae) are small and thin. Usually dark green in color.
Habitat and behavior: It has velcro-like hooks all over its body called setae that help it attach sessile organisms and algae.
graceful rock crab
Scientific name: Metacarcinus gracilis
Family: Canceridae
Phylum: Arthropoda
Typical size: Carapace width up to 11 centimeters
Depth range: Intertidal to 174 meters
Description: Similar to the Dungeness crab, the graceful crab has 5 teeth between the eyes. The graceful crab’s carapace is widest at the 9th tooth, with a 10th tooth that is visible behind the 9th. The Dungeness crab is widest at the 10th tooth. Similar in shape, design, and color to the Dungeness crab, the graceful crab has white tips of the chelae and sometimes the legs look purple in color. They are generally smaller than Dungeness.
Habitat and behavior: Found in sand, mud, or sometimes eelgrass or pilings. Scavengers. Cannot osmoregulate and do not tolerate brackish water.
grainy hand hermit crab
Scientific name: Pagurus granosimanus
Family: Paguridae
Phylum: Arthropoda
Typical size: Body up to 4 centimeters long.
Depth range: 0 to 35 meters
Description: They have a greenish-brown body and arms with light blue raised dots all over it. It also has orange or red antennae.
Habitat and behavior: Lives from Aleutian Islands to Baja California. They will live in rock, sand and in algae.
helmet crab
Scientific name: Telmessus cheiragonus
Family: Atelecyclidae
Phylum: Arthropoda
Typical size: Carapace diameter up to 10 centimeters
Depth range: Intertidal to 110 meters
Description: A few teeth are present between the eyes, but no rostrum (protrusion) as with other true crabs. The 5 sided carapace is green/yellow/brown/orange/red in color and covered by small hairs, down to the legs and pinchers (chelipeds). The chelipeds are shorter than the walking legs, with the right being larger than the left.
Habitat and behavior: Found on algae like lettuce leaf or clinging to eelgrass. Can bury in the sand. Predators include sea otters and fur seals.
longhorn decorator crab
Scientific name: Chorilia longipes
Family: Majidae
Phylum: Arthropoda
Typical size: The carapace is about 4.25 centimeters wide
Depth range: subtidal to about 1,170 meters deep
Description: The crab’s carapace is spiny and resembles the shape of a teardrop with two long, horn-like protrusions. No prominent spines behind the eyes like the graceful decorator crab (Oregonia gracilis). It’s color is a pale orange and its legs often are banded with white. Front legs are longer than the others, with slender claws (chelae) that have red bands.
Habitat and behavior: Typically found on rocky reefs, boulders, and sandy bottom. The longhorn decorator crab often camouflages itself with sponges and seaweed to hide from predators. It has velcro-like hooks all over its body called setae that help it attach sessile organisms.
northern kelp crab
Scientific name: Pugettia producta
Family: Epialtidae
Phylum: Arthropoda
Typical size: Carapace ranges 2 to 10 centimeters in width
Depth range: 0 to 80 meters
Description: The northern kelp crab is usually a dark brown, red, or green color depending on the food it eats. Its body is relatively small compared to its long, skinny legs with small claws. The carapace has two hooks on either side with an otherwise smooth shell.
Habitat and behavior: It lives mostly in kelp beds but is also common on pilings. The northern kelp crab uses its pointy legs to grab onto kelp such as bull kelp, eelgrass, or sea lettuce and feed off of this algae. While they look similar to decorator crabs, they do not decorate themselves except for a few pieces of kelp they may stick to their head to save as a snack for later.
puget sound king crab (Juvenile)
Scientific name: Lopholithodes mandtii
Family: Lithodidae
Phylum: Arthropod
Typical size: 2 to 5 centimeters
Depth range: Subtidal to 150 meters
Description: Bumpy carapace with 8 legs and 2 claws. The juvenile is bright orange.
Habitat and behavior: The juvenile Puget Sound king crab is shy and hides from predators in rocky subtidal areas. Sometimes found in areas with strong currents.
puget sound king crab (adult)
Scientific name: Lopholithodes mandtii
Family: Lithodidae
Phylum: Arthropod
Typical size: 15 to 30 centimeters
Depth range: Subtidal to 150 meters
Description: Bumpy carapace with 8 legs and 2 claws. Bright red, orange, and purple in color.
Habitat and behavior: Live in rocky subtidal areas, sometimes with strong currents. In late fall they move closer to shore to molt and find mates.
red rock crab
Scientific name: Cancer productus
Family: Canceridae
Phylum: Arthropoda
Typical size: Up to 20 centimeters wide
Depth range: Intertidal to 90 meters
Description: The body is bright red, brick red, or red-purple and chelae (pinchers) have black tips. Juveniles can vary in color. The carapace is fan shaped, with ridges along the front side. The carapace is widest in the middle of these ridges, while the Dungeness crab is widest at the last spine of the carapace. Walking legs are shorter than the chelipeds.
Habitat and behavior: Males will guard a female who is preparing to molt by holding her until they are ready to mate. Red rock crabs are found in sandy or rocky areas near barnacles and in low salinity areas as they cannot osmoregulate. Usually in shallower areas. Sometimes epibionts (symbiotic organisms that live on the surface) such as barnacles are found on carapaces.
Scaled crab
Scientific name: Placetron wosnessenkii
Family: Hapalogastridae
Phylum: Arthropoda
Typical size: 7.2 centimeters
Depth range: Up to 110 meters
Description: They are dark green/gray/brownish with a wide body. Their backs look like they are covered with scales. Claws or chelae are scooped like spoons. They have long antennae.
Habitat and behavior: They live from Pribilof Islands to Puget Sound. They will eat brittle stars and live on rock faces.
sharp nosed crab (Elbow crab)
Scientific name: Scyra acutifrons
Family: Majidae
Phylum: Arthropoda
Typical size: Carapace width up to 5 centimeters
Depth range: Subtidal to 220 meters
Description: Long, flat rostrum (nose-like protrusion from head). Triangular shaped carapace with two mounds on either side that is red or brown but usually overgrown. Chelipeds (pinchers) are longer than the walking legs. The legs are thin and have sharp ends. The elbows of the chelipeds are sometimes a lighter color than the rest of the body, and with the claws pointed in towards the crabs mouth, stick out to earn the name “elbow crab”.
Habitat and behavior: The sharp nosed crab is not technically a decorator crab, as it does not decorate itself but the carapace can become overgrown with ascidians/tunicates, sponges, and bryozoans because this crab does not molt as an adult. Sometimes, it does stick small pieces of algae on its rostrum to save as a snack for later. Found on sea anemones, including the giant plumose anemone, and is preyed on by rockfish.