Striped Shore Crab
Pachygrapsus crassipes
Classification
- Phylum: Arthropoda
- Subphylum: Crustacea
- Class: Malacostraca
- Superorder: Eucarida
- Order: Decapoda
- Infraorder: Brachyura
- Family: Grapsidae
- Genus: Pachygrapsus
- Species: crassipes
Pronunciation
How to pronounce Pachygrapsus crassipes: /ˌpækiˈɡræpsəs ˈkræsɪpiːz/
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Summary
Pachygrapsus crassipes, or the striped shore crab, is a small crab notable for its distinctive striped carapace and significant ability to survive on land for extended periods. It exhibits diverse feeding behaviors depending on its habitat, demonstrating both predatory and herbivorous tendencies.
Physical Characteristics
Typically, this crab has a brown/purple or black carapace with green stripes. Its carapace is square and can reach 4 to 5 cm in size. The claws are red/purple with a mottled and striped pattern on the upper surface, and whitish-grayish on the lower surface. Its legs are purple and green with a similar mottled appearance.
Identification Tips
Unique among grapsids in having transverse lines on its carapace and two teeth rather than three on the anterolateral margin of its carapace.
Habitat
Found on rocky and hard-mud soft seashores of the northeastern and northwestern Pacific Ocean.
Distribution
From central Oregon south through California to near Ensenada, Baja California, Mexico. An isolated population exists at Bamfield on Vancouver Island, Canada.
Diet
Opportunistic predator, diet includes green algae, red algae, brown seaweed, diatoms, worms, mussels, small decaying organisms, limpets, snails, flies, hermit crabs, seaweed, isopods, and occasionally others of its species when the lesser crab has just finished molting.
Predators
Seagulls, octopuses, rats, raccoons, and humans.
Ecosystem Role
Plays a role in the intertidal ecosystem as both predator and prey, helping to control algae populations and serving as food for various predators.
Evolution
Western Pacific population diverged from the eastern Pacific population approximately 0.8 to 1.2 million years ago.
Tags
- striped shore crab
- Pachygrapsus crassipes
- grapsid crab
- marine crustacean