Conservancy Fairy Shrimp

Branchinecta conservatio

Description

Branchinecta conservatio (Conservancy fairy shrimp), a member of the family Branchinectidae, was first described from specimens collected at the Jepson Prairie Preserve, located in the Central Valley east of Travis Air Force Base in Solano County.

The earliest known collections of the Conservancy fairy shrimp were made in 1979. This shrimp ranges in size from 0.6-1.1 in (14-27 mm) long and is most similar in appearance to Lindahl's fairy shrimp (B. lindahli ). However, the female brood pouch is fusiform and usually ends under abdominal segment eight in the Conservancy fairy shrimp, whereas the pouch is cylindrical and usually ends under segment four in Lindahl's fairy shrimp. The large, oval pulvillus at the proximal end of the basal segment of the male antenna appears similar in both species, however, the terminal end of the distal antennal segments of the Conservancy fairy shrimp are distinctive.

Behavior

The Conservancy fairy shrimp has been observed from November to early April. It is usually collected at cool temperatures and appears to be relatively long-lived.

Habitat

The Conservancy fairy shrimp inhabits vernal pools with highly turbid water. The pools at Jepson Prairie and Vina Plains inhabited by this animal have very low conductivity, total dissolved solids, and alkalinity.

Distribution

The species is known from six disjunct populations: Vina Plains, Tehama County; south of Chico, Tehama County; Jepson Prairie, Solano County; Sacramento National Wildlife Refuge, Glenn County; near Haystack Mountain northeast of Merced in Merced County; and the Lockewood Valley of northern Ventura County. The pools inhabited by the Conservancy fairy shrimp are large, such as the 89-acre (36-hectare) Olcott Lake at Jepson Prairie. Four of the six known populations of the Conservancy fairy shrimp are imperiled, and three of the six populations are comprised of single or less than five pools.

Threats

Proposed highway construction in Solano County could damage vernal pools inhabited by the Conservancy fairy shrimp. The State of California has proposed to extend State Highway 505 from Vacaville to Collinsville in Solano County; this project directly and/or indirectly would impact vernal pools inhabited by the Conservancy fairy shrimp. In Solano County, an off-road vehicle park adjacent to the Jepson Prairie Reserve owned by the Nature Conservancy (TNC) could adversely impact populations of the Conservancy fairy shrimp.

Conservation and Recovery

The Conservancy fairy shrimp is known from habitats in Jepson Prairie Preserve, owned by TNC (a private conservation organization), and on federally owned Sacramento National Wildlife Refuge and Travis Air Force Base. The federally owned habitats should be strictly protected against any threatening influences. Other non-federal habitats are threatened by various development activities. The largest of the privately owned habitats should be protected. This could be done by acquiring the land and establishing ecological reserves, or by negotiating conservation easements with the landowners. The known populations of the Conservancy fairy shrimp should be monitored, and research undertaken into its biology and habitat needs.

Contacts

U. S. Fish and Wildlife Service
Sacramento Fish and Wildlife Office
Federal Building
2800 Cottage Way, Room W-2605
Sacramento, California 95825-1846
Telephone: (916) 414-6600
Fax: (916) 460-4619

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Building
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
Telephone: (503) 231-6121
http://pacific.fws.gov/

Reference

U.S. Fish and Wildlife Service. 19 Sept. 1994. "Endangered and Threatened Wildlife and Plants; Determination of Endangered Status for the Conservancy Fairy Shrimp, Longhorn Fairy Shrimp, and the Vernal Pool Tadpole Shrimp; and Threatened Status for the Vernal Pool Fairy Shrimp." Federal Register http://www.cdpr.ca.gov/docs/es/estext/fr091994.txt