Hemigrapsus oregonensis (Dana, 1851)

Wicksten, Mary K., 2012, Decapod Crustacea of the Californian and Oregonian Zoogeographic Provinces 3371, Zootaxa 3371, pp. 1-307 : 265-267

Hemigrapsus oregonensis (Dana, 1851)

( Fig. 61D, Pl. 15F)

Pseudograpsus oregonensis Dana, 1851: 248 ; 1852: 334; 1855: pl. 20, fig. 6.

Brachynotus oregonensis . — Holmes 1900: 82.

Hemigrapsus oregonensis . — Rathbun 1904: 189; 1917: 270, pl. 70. — Weymouth 1910: 63, pl. 14, fig. 43. — Schmitt 1921: 274, text fig. 162, pl. 48. — Johnson & Snook 1927: 396, fig. 352. — Garth & Abbott 1980: 621, fig. 25.45. — Hart 1982: 220, fig. 91.— Ricketts et al. 1985: 358, fig. 275. — Campos & de Campos 1989: 174. — Bonfil et al. 1992: 39, fig. 1B. — Jensen 1995: 17, fig. 2. — Kuris et al. 2007: 641.

Diagnosis. Carapace more or less square, smooth, with 2 lateral teeth posterior to postorbital tooth. Front with deep median sinus. Chelipeds smooth, adult male with rounded lobe on antero-internal angle of merus, patch of setae on inner surface of propodus; fingers of cheliped curved, with teeth, spooned. Pereopods 2–5 with coarse, sparse setae, dactyls narrow. Male carapace length to 29 mm, female smaller.

Color in life. Greenish to muddy gray, sometimes with minute black dots; fingers of chela white, without redpurple spots ( Hart, 1982).

Habitat and depth. Salt marshes, mud flats; quiet, protected tide pools, gravel flats, intertidal zone.

Range. Resurrection Bay , Alaska to Tortugas Bay, Baja California, Mexico. Type locality Puget Sound .

Remarks. In bays and harbors, H. oregonensis can occur by the hundreds.