Petrolisthes eriomerus Stimpson, 1871

Wicksten, Mary K., 2012, Decapod Crustacea of the Californian and Oregonian Zoogeographic Provinces 3371, Zootaxa 3371, pp. 1-307 : 158

Petrolisthes eriomerus Stimpson, 1871

( Fig. 37C, Pl. 8C)

Petrolisthes eriomerus Stimpson, 1871: 119 . — Lockington 1878: 395. — Holmes 1900: 108, pl. 1, fig. 15. — Rathbun 1904: 168. — Schmitt 1921: 180 (in part), pl. 23, fig. 2, fig. 114. — Johnson & Snook 1927: 351, fig. 299. — Haig 1960: 74, pl. 26, fig. 4. — Gonor & Gonor 1973: 225. — Haig & Abbott 1980: 587, fig. 24.15. — Hart 1982: 96, fig. 32. — Ricketts et al. 1985: 306. — Jensen 1995: 75, fig. 150. — Kuris et al. 2007: 648.

Diagnosis. Front broad, triangular, with deep median groove. Carapace about as long as wide, anterior part covered with rough granules, posterolateral areas plicate. Chelipeds covered with large granules. Merus with strongly projecting lobe on anterior margin. Carpus twice as long as wide, margins subparallel; outer margin serrate, ending in distal tooth. Chela naked, gape filled with thick pubescence. Pereopods 2–4 granular, merus not inflated, all segments with setae. Carapace length to 19 mm.

Color in life. Granules on carapace red-brown or white with blue tinges in grooves, blue, white comma-like mark on either side of cardiac region. Chelipeds with dark, light red granules; orange areas, blue-white patches at junctions of segments; blue spot at base of dactyl. Pereopods 2–4 brown with 2 patches of yellow on merus; red, yellow band proximally, yellow distally on propodus; dactyl brown, yellow. Outer maxillipeds with both surfaces of last two articles bright blue ( Hart 1982). Individuals ready to molt may be bluish.

Habitat and depth. Under rocks in lowest intertidal zone, rarely to 86 m.

Range. Chicagof I., Alaska to La Jolla, California . Type locality Mendocino , California .