When burrowing, swimming, or crawling, it always moves backwards.

Pacific Sand Crab (Mole Crab)

Emerita analoga

Decapoda: Hippidae

Laguna Beach, Orange County, CA. 06/11/06. © Peter J. Bryant.
Back to Natural History of Orange County, California
Back to Crustacea index page

A very common and familiar burrowing crab on sandy beaches in Southern California, showing some impressive adaptations for its sandy habitat. Sand crabs are a major food source for shore birds and for some kinds of fish.

Its eyes are on long stalks and its antennules are long enough that it can keep them above the surface even after it has burrowed backwards into the sand.

The antennules form a tube though which water is directed downwards into the gill chambers.

Its legs and uropods have hairy margins for rapid digging in the sand, for filtering food and transferring it to the mouth.

Although not very conspicuous, they are one of the most abundant animals on sandy beaches of Southern California

When the crab is covered by a wave, the antennae are extended out over the sand to collect food.

The antennae are much bigger than the antennules, which are visible here in the center.

After the wave retreats, the antennae are quickly coiled and retracted into the body. Here only one is being retracted.