Shield-Backed Kelp Crab

Shield-Backed Kelp Crab (Pugettia producta)

Contributed by TPERP Dan Wieder

Identification: The body is shield-shaped, with a long pointed spine. Its color can range from olive-green to deep reddish brown. There are dark spots and blotches on an smooth surface.

Size: Can be up to 4 inches in size.

Range and Habitat: Alaska to Central Baja California. Found on rocks and in giant kelp in the low intertidal to about 250 feet down (75 m). These are occasionally found hiding out in the surfgrass at Cabrillo. Sometimes they are the victims of heavy foot traffic during busy days at very low tide and great weather. Even the rangers have been guilty of stepping on them sometimes. The population is probably not in any danger, though.

Natural History: This is a herbivore feeding on brown algae. Females can produce offspring every 30 days and can hold as many as 30,000 to 80,000 eggs.

On this same specimen you can see the barnacles have their filters out trying to catch morsels of food.


Phylum: Arthropoda

Class: Malacostraca

Order: Decapoda

Family: Epialtidae

Scientific Name: Pugettia producta

Common Name(s): Shield-Backed Kelp Crab


Literature Cited

Jeffery L. Brandon, and Rokop, F. J. Life Between the Tides – The Natural History of the Common Seashore Life of Southern California. 1985. American Southwest Publishing Company of San Diego.

Last revised 23-Dec-15