One morning in June I was wandering around the outer shores during a very low tide, forecast to be -2.3 feet. You can get a sense of this in the photo below. A low tide like this always brings out a few people looking for stuff to harvest on the sandy beaches.

A sandy foreground, cloudy skies, and sea stacks in the distance
Early morning minus tide; iconic sea stacks stretch into the distance

They’re usually looking for crabs and clams and sometimes, when they’re digging around looking for food, they unearth food for other sand-dwellers that inhabit the shore. That’s how I encountered the Pacific mole crab, Emerita analoga, shown in the photos below.

on wet sand
Pacific mole crab, ventral view

Some authors call them Pacific mole crabs and some call them Pacific sand crabs, either way, they’re Emerita analoga. In the ventral view above, the head is pointing down and to the left. I’m not sure what sex this one is but there were no eggs present. I showed a ventral view of a female with eggs in a recent post, An Abundance of Orange. You can go there and see what you think.

on wet sand
Pacific mole crab, dorsal view

This one seemed a bit disoriented and slightly injured when I found it. Here, the head is pointing down. You can see the dislocated lower right appendage. Nevertheless, it was ready to bury itself as soon as I released it. They burrow rear-end first, as you can see in the photo below, and it happens fast. It was going, gone.

In wet sand
Pacific mole crab, going
Burrowed beneath wet sand
Pacific mole crab, gone

Whenever they are present, mole crabs and their eggs are food to predators that roam the outer shores. Surfperch love them when they can get them. I learned a lot by reading Larval dynamics of the sand crab, Emerita analoga, off the central Oregon coast during a strong El Niño period.

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