Syncaris pacifica

Appearance

This species is often translucent to transparent, with both sexes capable of considerable coloration altering, as a sophisticated form of camouflage.

The species has a superficial appearance to its better known marine relatives, and may attain a body length of about 5 centimetres (2.0 in).

Range and habitat

The precise historic distribution of Syncaris pacifica is not known, since geologic and climatic changes since the early Quaternary Period have significantly altered river courses of the Northern California coast. Historically, Syncaris pacifica may have occurred as far north as the Klamath River, but reductions of habitat, especially from overgrazing of cattle, along with chemical water pollution has greatly diminished the present range to 17 stream segments in Sonoma, Napa and Marin Counties, with the largest population currently being in Salmon Creek, Sonoma. Occurrence is restricted to perennial streams below 100 meters above sea level in elevation and of gradient less than one percent.

Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.

Habits

Freshwater crayfishes and crabs walk the bed. Dams, silt, and introduced species cut a drainage into fragments they cannot cross.

Crayfishes and crabs need cover and clean water. A named form from one creek is not interchangeable with the next drainage.

In crisis

This decapod is called California freshwater shrimp, and is the only extant decapod shrimp in California that occurs in non-saline waters (its congener Syncaris pasadenae from the basin of the Los Angeles River is extinct). Genetic studies have been conducted to compare specimens of Syncaris pacifica from various drainages, with the results showing a variety of well-defined genetic variations within these populations. Syncaris pacifica is a federally listed endangered species, protected under the Endangered Species Act of 1973 since its initial listing in 1988.

Conservation priorities for S. Pacifica and associated native aquatic species include: Protect and manage S. Pacifica populations and habitat once the threats are removed and restoration has been completed Monitor and evaluate S. Pacifica habitat conditions and populations.

Syncaris pacifica is Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.

Sources

Written for this catalog from the English Wikipedia article on Syncaris pacifica, Wikidata item Q3932537. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.