Crustaceans are invertebrates (which means they have no spine) that have jointed legs and a hard exoskeleton.  They come in many shapes and sizes.  Crustaceans’ body shapes are so varied that the only thing they all have in common is two pairs of antennae at some stage of their life cycle.  

You would probably recognize a crab, a lobster and a crawfish (crawdad) but few people realize how many crustaceans live in the world around us.  More than 38,000 species of crustaceans are known; most live in the ocean and many have not yet been named.

Several types of freshwater crustaceans live in vernal pools in the Central Valley.  You will discover a few here but there are many more.  Seek them out during the wet winter months when the pools are full of water.  They will be long gone by summer!

Clam Shrimp

A Clam Shrimp looks like a small clam.  Two shells cover its body.  Between the shells you can see two body sections below the head. ...


There are many different species of Copepods.  Few of the species in vernal pools have been named.  You are most likely to spot the

Fairy Shrimp

Fairy Shrimp are pale-colored (normally gray-white) and transparent.  They have a long, narrow body with 11 pairs of paddle-like legs. 

Seed Shrimp

Many different species of Seed Shrimp live in vernal pools.  They come in many colors.  They have a single eye.  The body of a Seed...

Water Flea

A Water Flea swims in a jerky, hopping motion like a flea.  A carapace (shell) covers most of its body.  The carapace is hinged on...