Fairy shrimp are easily identified in vernal pools. The adult fairy shrimp have stalked compound eyes, two sets of antennae, and 11 pairs of leaf-like swimming legs. Coloration is usually red-orange due to the hemoglobin in the shrimp, but can range from translucent whitish to gray, blue or green. Because coloration is determined by the contents of the food supply in the pool which the shrimp inhabit, it is usually constant among the individuals of the pool.
Male shrimp possess an enlarged second antenna used to clasp the female during mating.
Female fairy shrimp often have a brood sack on their abdomen. Female fairy shrimp usually outnumber males. They are capable of three states of mobility. Resting at the bottom of the pools, darting rapidly and drifting slowly. By changing the angle of these exopodites the speed of motion can be changed.