Striped Shore Crab (Pachygrapsus crassipes)

Description: Striped or lined shore crabs have dark reddish-purple to black legs and claws as well as dark backs striped with thin bright-green horizontal lines. They have two spikes on each side of their body near the front of the carapace. Male striped shore crabs can reach almost 5 cm in width and females reach about 4 cm in width, making these a rather small variety of crab.

Habitat: Striped shore crabs are a common intertidal species of crab found along the Pacific coast from Oregon down to Baja California, Mexico. On the other side of the Pacific Ocean, striped shore crabs are found along the Japanese and Korean coastlines. At Haystack Rock, striped shore crabs can be found hiding in crevices, like between rocks or within mussel beds.

Diet: They use their tiny but mighty pincers to tear up pieces of algae for food, but sometimes they’ll also eat creatures like limpets and even other small crabs.

Tide Pool Tidbits:

• These crabs are often seen bubbling at the mouth. This is common behavior in species that spend a considerable amount of time out of the water. In order to keep their gills wet while still absorbing the oxygen they need to breathe, they will often blow air over the water in their gills to aerate the water.

• Each female can produce up to 50,000 eggs in one clutch!

References: iNaturalist, Morro Bay NEP, Walla Walla University, Biology Insights