Branchinecta longiantenna
Encyclopedia
Branchinecta longiantenna is a rare species of crustacean
in the family Branchinectidae
and the order Anostraca, the fairy shrimp. Its common name is longhorn fairy shrimp. It is endemic to California
in the United States
, where there are only four known populations. It is a federally listed endangered species
of the United States.
This fairy shrimp is between one and two centimeters in length and differs from other fairy shrimp in the shape of its antenna
e. The animal lives in vernal pool
s on grassland
s as well as pools on sandstone
substrates. The fairy shrimp takes at least 23 days to reach maturity, and about 43 days on average.
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 Plain
. Several are protected, and some are unprotected on private property. In Merced County
in the Central Valley, the species can be found within the San Luis National Wildlife Refuge
, where it is protected. In Contra Costa County
the species is present in several vernal pools and can be found in scattered water-filled rock indentations. This population is protected in a preserve. In Alameda County
the fairy shrimp occurs in vernal pools in a preserve, where it is protected. In addition to these four populations, one individual fairy shrimp was located near Los Banos
in 2003, but it probably does not indicate the presence of a new population.
This species is at risk for extinction
because it has few small populations and the extirpation
of any one could greatly reduce the total population.
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
in the family Branchinectidae
Branchinectidae
Branchinectidae is a family in the order Anostraca , containing two genera – Branchinecta and Archaebranchinecta. The majority of the species are in the genus Branchinecta, with only Archaebranchinecta pollicifera and the fossil Archaebranchinecta barstowensis in the second genus....
and the order Anostraca, the fairy shrimp. Its common name is longhorn fairy shrimp. It is endemic to California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, where there are only four known populations. It is a federally listed endangered species
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
of the United States.
This fairy shrimp is between one and two centimeters in length and differs from other fairy shrimp in the shape of its antenna
Antenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
e. The animal lives in vernal pool
Vernal pool
Vernal pools, also called vernal ponds or ephemeral pools, are temporary pools of water. They are usually devoid of fish, and thus allow the safe development of natal amphibian and insect species...
s on grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
s as well as pools on sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
substrates. The fairy shrimp takes at least 23 days to reach maturity, and about 43 days on average.
There are four populations in California, all well separated from each other. In San Luis Obispo County
San Luis Obispo County, California
San Luis Obispo County is a county located along the Pacific Ocean in the Central Coast of the U.S. state of California, between Los Angeles and the San Francisco Bay Area. As of the 2010 census its population was 269,637, up from 246,681 at the 2000 census...
the fairy shrimp occurs in vernal pools on the Carrizo Plain
Carrizo Plain
The Carrizo Plain is a large enclosed plain, approximately 50 miles long and up to 15 miles across, in southeastern San Luis Obispo County, California, about 100 miles northwest of Los Angeles, California...
. Several are protected, and some are unprotected on private property. In Merced County
Merced County, California
Merced County , is a county located in the Central Valley of the U.S. state of California, north of Fresno and southeast of San Jose. As of the 2010 census, the population was 255,793, up from 210,554 at the 2000 census. The county seat is Merced...
in the Central Valley, the species can be found within the San Luis National Wildlife Refuge
San Luis National Wildlife Refuge
The San Luis National Wildlife Refuge in the San Joaquin Valley of central California is one of the great remnants of a historically bountiful wintering grounds for migratory waterfowl on the Pacific Flyway...
, where it is protected. In Contra Costa County
Contra Costa County, California
Contra Costa County is a primarily suburban county in the San Francisco Bay Area of the U.S. state of California. As of the 2010 census, it had a population of 1,049,025...
the species is present in several vernal pools and can be found in scattered water-filled rock indentations. This population is protected in a preserve. In Alameda County
Alameda County, California
Alameda County is a county in the U.S. state of California. It occupies most of the East Bay region of the San Francisco Bay Area. As of the 2010 census it had a population of 1,510,271, making it the 7th most populous county in the state...
the fairy shrimp occurs in vernal pools in a preserve, where it is protected. In addition to these four populations, one individual fairy shrimp was located near Los Banos
Los Banos, California
Los Banos is a city in Merced County, California, near the junction of State Route 152 and Interstate 5. Los Banos is located southwest of Merced, at an elevation of 118 feet . The population was 35,972 at the 2010 census, up from 25,869 at the 2000 census...
in 2003, but it probably does not indicate the presence of a new population.
This species is at risk for extinction
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
because it has few small populations and the extirpation
Local extinction
Local extinction, also known as extirpation, is the condition of a species which ceases to exist in the chosen geographic area of study, though it still exists elsewhere...
of any one could greatly reduce the total population.
External links
- Inland Water Crustacean Specialist Group 1996. Branchinecta longiantenna. 2011 IUCN Red List of Threatened Species. Downloaded on 3 September 2011.