Pacific Sand Crab (Emerita analoga)

The Pacific sand crab lives under the surface of the sand of beaches in Point Reyes National Seashore. Moving up and down the beach according to the state of the tide, they try to feed while avoiding predators. As each wave advances and retreats, the crab comes to the surface and extends its antennae to feed. It is at this point that it is most vulnerable to resident herons and ravens as well as the migratory birds such as sanderlings, godwits, surf scoters, curlews, etc. that stop at Point Reyes NS to replenish their reserves during the migration.

These birds actively patrol the part of the beach washed by incoming waves, probing the softened sand with their bills. The sand crab tries to avoid them by retreating under the sand surface as each wave goes out.

Due to it’s diet, the sand crab can act as an indicator species for monitoring the level of domoic acid-synthesizing diatoms (Pseudo-nitzschia spp.) which sometimes cause toxic blooms off the coast of California.