Striped Shore Crab

Pachygrapsus crassipes

Classification

Pronunciation

How to pronounce Pachygrapsus crassipes: /ˌpækiˈɡræpsəs ˈkræsɪpiːz/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Pachygrapsus crassipes 000 by Franco Folini. Used under a CC BY 2.5 license.
Ecdysis Pachygrapsus crassipes by Tatsundo h. Used under a CC BY-SA 3.0 license.
Pachygrapsus crassipes (23470066989) by USFWS - Pacific Region. Used under a Public domain license.
Pachygrapsus crassipes MB CA by Jerry Kirkhart from Los Osos, Calif.. Used under a CC BY 2.0 license.
Pachygrapsus crassipes (2133035980) by Jerry Kirkhart from Los Osos, Calif.. Used under a CC BY 2.0 license.
Pachygrapsus crassipes Hearst beach by Peter D. Tillman. Used under a CC BY-SA 3.0 license.

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