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.
Picture of small pool, many individuals in small pool on granite outcrop. Keyed to genus using Thorp and Covich.
The "Lago di Pilato" is a lake in a deep u-shaped valley below Monte Vettore, a mountain in the Italian Central Apennines.
There are two basins that sometimes are connected. When I took the picture, in June 2007, the two basins were not connected.
The two basins were connected in June 2009 (?), see this picture http://www.flickr.com/photos/33434902@N04/3624776024/ by Fabrizio Di Meo.
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...