Syncaris pacifica (Holmes, 1895)

Wicksten, Mary K., 2012, Decapod Crustacea of the Californian and Oregonian Zoogeographic Provinces 3371, Zootaxa 3371, pp. 1-307 : 50-51

Syncaris pacifica (Holmes, 1895)

( Fig. 11H)

Miersia pacifica Holmes, 1895: 577 .

Syncaris pacifica . — Holmes 1900: 211. — Hedgpeth 1968: 511, figs. 1, 2. — Standing 1981: 775. — Eng 1981: 1, fig. 1. — Martin & Wicksten 2004: 447, figs. 6–9 (extensive synonymy). — Kuris et al. 2007: 638, pl. 316C, 318 I.

Diagnosis. Body slender. Rostrum with 1–2 dorsal, 5–9 ventral teeth, slender, about as long as carapace. Carapace with supraorbital, antennal, pterygostomian teeth. Stylocerite longer than first segment of antennular peduncle. Scaphocerite about as long as rostrum. Pereopods 1–4 with exopods, epipods; pereopod 5 without exopods. Pereopod 1 short, carpus short, distally widened, concave; chela when flexed folding against concavity of carpus. Pereopod 2 longer than pereopod 1, carpus shorter than chela. Pereopods 3–5 subequal, dactyls short, with spinules; merus of pereopod 3 with 3 spines, merus of pereopods 4, 5 with 2 spines each. Abdominal somites rounded. Telson with truncate or broadly rounded apex, with 2 short dorsolateral spines, 2 pairs terminal spines. Total length 50 mm.

Color in life. Transparent to rust-colored, with scattered chromatophores, pale band at base of tail fan.

Habitat and depth. Coastal streams, shallow water.

Original range. Napa, Sonoma and Marin counties, California (see Martin & Wicksten 2004 for map) . Type locality Sonoma County, California .

Remarks. Syncaris pacifica , the California freshwater shrimp, is endangered due to habitat destruction and introduction of predatory fishes. The shrimp usually occur in slower reaches of streams, where they cling to aquatic vegetation and roots ( Hedgpeth 1968, Eng 1981).