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Amphipods: Amphipoda

Beach Hopper (orchestoidea Californiana): Species Accounts

Physical characteristics: Beach hoppers measure up to 1.1 inches (28 millimeters) in length. They have curved bodies that are flat from side-to-side. Their compound eyes are very small. The long second pair of antennae is bright orange to rosy red.

Geographic range: Beach hoppers are found along the west coast of North America, from Vancouver Island, British Columbia, south to Laguna Beach, California.

Habitat: They live on beaches with fine sand and backed by dunes.

Diet: They eat seaweed washed up on the beach.

Beach hoppers feed at night to avoid both the daytime heat and being eaten by shorebirds. (Illustration by John Megahan. Reproduced by permission.)

Behavior and reproduction: Beach hoppers feed at night to avoid both the daytime heat and being eaten by shorebirds. Adults burrow down to 12 inches (300 millimeters) beneath the surface and stay there during the day. They jump by using the rear of their abdomens and their uropods as a spring.

Adults mate in their burrows from June until November. The male deposits a jellylike mass of sperm on the underside of the female and soon leaves the burrow. The dark blue eggs are brooded inside a pouch made by broad, leaflike appendages on the thorax. Newly hatched juveniles closely resemble the adults.

Beach hoppers and people: Beach hoppers do not impact people or their activities.

Conservation status: The World Conservation Union (IUCN) does not consider beach hoppers to be threatened or endangered. ∎



Brusca, R. C., and G. L. Brusca. Invertebrates. Second edition. Sunderland, MA: Sinauer Associates, Inc., 2003.

Morris, R. H., D. P. Abbott, and E. C. Haderlie. Intertidal Invertebrates of California. Stanford, CA: Stanford University Press, 1980.


Holsinger, J. R. "The Freshwater Amphipod Crustaceans (Gammaridae) of North America." Biota of Freshwater Ecosystems, Identification Manual No. 5, Environmental Protection Agency (1972): 17-24.

Web sites:

Amphipoda (Pericarida, Malacostraca). http://www.crustacea.net/crustace/www/amphipod.htm (accessed on March 22, 2005).

The Biology of Amphipods. http://www.mov.vic.gov.au/crust/amphbiol.html (accessed on March 22, 2005).

Endangered Species Bulletin. "Endemic Amphipods in Our Nation's Capital—Brief Article." http://endangered.fws.gov/esb/2002/01-02/toc.html (accessed on March 22, 2005).

Subterranean Amphipod Database. http://web.odu.edu/sci/biology/amphipod/ (accessed on March 22, 2005).

Additional topics

Animal Life ResourceMollusks, Crustaceans, and Related SpeciesAmphipods: Amphipoda - Physical Characteristics, Behavior And Reproduction, Conservation Status, Skeleton Shrimp (caprella Californica): Species Accounts - GEOGRAPHIC RANGE, HABITAT, DIET, AMPHIPODS AND PEOPLE