High numbers in this closed depressions wetland
Invertebrates swimming in pools of water on top of a large, bare-faced granite dome. Small (larger than a mosquito larva), propelled by numerous cilia.
Captive, not wild.
Close-up photo of head shows the amplexial appendages of a male. The photo of the entire fairy shrimp is a female with eggs.
Imperial County, California, US
There's a small vernal pool on the pathway at the top of the mesa. It was teaming with fairy shrimp. I've never seen shrimp in that pool since. In fact, I don't even see the pool in most years. Tentatively IDed as the San Diego Fairy Shrimp, based on geography and consultation with one D.C. Rogers.
I suppose there are more pools on the mesa, beyond the fence line.
Anostraca is one of the four orders of crustaceans in the class Branchiopoda; its members are also known as fairy shrimp. They are usually 6–25 mm (0.24–0.98 in) long (exceptionally up to 170 mm or 6.7 in). Most species have 20 body segments, bearing 11 pairs of leaf-like phyllopodia (swimming legs), and the body lacks a carapace. They live in vernal pools and hypersaline lakes across the world, including pools in deserts, in ice-covered mountain lakes and in Antarctica. They...