Make no mistake, despite its small size, the Riverside fairy shrimp (Streptocephalus woottoni) is a crustacean tough enough to withstand one of nature’s most unpredictable habitats. Averaging just three quarters of an inch in size, these shrimp are excellent swimmers, perfectly suited for life in the seasonal pools they call their home. Seasonal pools are temporary bodies of water varying in size from a small puddle to a shallow pond depending on seasonal rainfall amounts.

Unlike many of their aquatic cousins, the Riverside fairy shrimp has a rosy-translucent body with cylindrical front appendages that are bent down at the tips. The Riverside fairy shrimp’s unique color stems from the red jointed appendages, called cercopods, on their body that assist in steering their rudder-like abdomen. These cercopods allow the shrimp to breeze through the pools with agility, making them efficient hunters. These crustacean champions can move swiftly to snatch up morsels of algae, bacteria, protozoa, rotifers, and other tiny morsels from the water.

Female Riverside fairy shrimp are slightly smaller than males and release eggs, or cysts, into the water column of their pool. Once fertilized, the eggs fall to the bottom of the pool where they eventually settle into the sediment as the pool dries. These eggs can remain dormant persisting in the soil for months, years, or even decades, waiting until the return of rain and favorable pool conditions, like preferred water temperature, that trigger hatching. Once the pools refill with rainwater – typically between January and March, the shrimp hatch within one to two weeks. They grow quickly, reaching full size in a period 2 to 3 weeks, depending on temperature and food abundance. In just 7 or 8 weeks, the Riverside Fairy shrimp completes its life cycle. With the next wet season, the cycle begins anew!

While Riverside fairy shrimp are found in pools across Riverside, Ventura, Orange, and San Diego counties, they are limited to their birth pool for their whole lives. Occasionally, their cysts are transported by wildlife, such as waterfowl, who may eat or unknowingly carry the eggs on their bodies to new locations. Cysts are hardy and can withstand the elements and environmental challenges, allowing them to hatch in new locations if the conditions are right.

Within western Riverside County, this MSHCP protected species have been spotted at the Santa Rosa Plateau, and locations in Murrieta, Wildomar, Lake Elsinore, Alberhill, and in Skunk Hollow, just east of the I-15 near Temecula. Thanks to the MSHCP, 11,942 acres of habitat have been described for conservation to support this species, making the future of this unique and resilient crustacean brighter!