Vernal Pool Fairy Shrimp

Vernal pool fairy shrimp are usually translucent, however some have been observed to be white or orange. They feature stalked compound eyes, no carapace, and eleven pairs of legs. Male fairy shrimp can be identified by large antennae called claspers, which distinguish them from their female counterparts. The fairy shrimp swim by moving their legs from front to back in a wave-like motion. They are known for their unique swimming orientation, as they swim "upside down." Vernal pool fairy shrimp require cooler water with low alkalinity and low total dissolved solids that can often be found in smaller pools about six inches deep. The vernal pool fairy shrimp's natural predators include the vernal pool tadpole shrimp, or Lepidurus packardi, salamanders, and beetle larvae. Vernal pools are the ideal habitat for vernal pool fairy shrimp, as they typically cannot sustain larger aquatic predators that may pose a threat to the shrimp due to their drying tendencies.

As suggested by their name, vernal pool fairy shrimp live in vernal pools vernal pools which are seasonal wetlands. These pools form when shallow basins are filled with seasonal precipitation, creating a short term habitat for fairy shrimp and other species that call vernal pools their home. Eventually, the vernal pools dry up and the habitat disappears until the next precipitation season. Vernal pool fairy shrimp have been found in southern Oregon, and parts of California. They can survive if the pool's temperature is between 43 °F (6 °C) and 68 °F (20 °C). In Oregon, they have been discovered in the Agate Desert, around Agate Lake, and on the Upper and Lower Table Rocks. In California, fairy shrimp have been found in 33 locations in the Central Valley from Shasta County to Tulare County, and in the Coast Range from Solano County to San Benito County. They have also been found near Soda Lake, Santa Barbara County, the Santa Rosa Plateau, San Diego County and Riverside County. Branchinecta lynchi can live in groups within the vernal pools of densities up to 200 shrimp per liter of water.

Vernal pool fairy shrimp eat algae, bacteria, protozoa, rotifers, and detritus. The fairy shrimp uses its legs to scrape food from hard surfaces. To help them digest their meals, they create a thick, glue-like substance to mix with their food.