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The vernal pool fairy shrimp, Branchinecta lynchi, is a species of freshwater crustacean in the family Branchinectidae. It is endemic to the U.S. states of Oregon and California, living in vernal pools as well as non-vernal pool habitat. They range in size from 0.43 to 0.98 inches (11 to 25 mm) long.
Conservancy fairy shrimp inhabit rather large, moderately turbid cool-water vernal pools which fill with water in the rainy season, then slowly dry up from their outer, more shallow edges to their deeper areas in the center. However, the shrimp are gone long before the pool finally dries up.
Anostraca is one of the four orders of crustaceans in the class Branchiopoda; its members are referred to as fairy shrimp. They live in vernal pools [ 3 ] and hypersaline lakes across the world, and they have even been found in deserts , ice-covered mountain lakes, and Antarctic ice. [ 4 ]
During the past geological periods clam shrimp were apparently more numerous and diverse than they are now. 300 extinct species are known, and half as many living species. The oldest clam shrimp, such as Asmussia murchisoniana, were found in Devonian deposits. Many extinct species, mostly Triassic specimens, once lived in marine environments ...
Clam shrimp are bivalved animals which have lived since at least the Devonian. The three groups are not believed to form a clade. They have 10–32 trunk segments, decreasing in size from front to back, and each bears a pair of legs which also carry gills. A strong muscle can close the two halves of the shell together.
Vernal pools, also called vernal ponds or ephemeral pools, are seasonal pools of water that provide habitat for distinctive plants and animals. They are considered to be a distinctive type of wetland usually devoid of fish, and thus allow the safe development of natal amphibian and insect species unable to withstand competition or predation by ...
As stated in the U.S. Fish and Wildlife Service's 1994 listing of four other vernal pool shrimp species (59 FR 48136), California's remaining vernal pools have been under severe pressure from urban development, agricultural conversion and associated hydrological changes. Losses of vernal pool habitat were noted prior to 1997. [7]
The animal lives in vernal pools on grasslands as well as pools on sandstone substrates. [3] The fairy shrimp takes at least 23 days to reach maturity, and about 43 days on average. [4] There are four populations in California, all well separated from each other. In San Luis Obispo County the fairy shrimp occurs in vernal pools on the Carrizo ...