Heptacarpus sitchensis ( Brandt, 1851 )

Wicksten, Mary K., 2012, Decapod Crustacea of the Californian and Oregonian Zoogeographic Provinces 3371, Zootaxa 3371, pp. 1-307 : 86

Heptacarpus sitchensis ( Brandt, 1851)

( Fig. 21F, Pl. 3C)

Hippolyte sitchensis Brandt, 1851: 116 , fig. 18.

Hippolyte picta Stimpson, 1871: 125 .

Heptacarpus pictus . — Holmes 1900: 200, pl. 3, figs. 54, 55. — Holthuis 1947: 13. — Word & Charwat 1976: 125. — Chace & Abbott 1980: 572, Fig. 23.7. — Ricketts et al. 1985: 85. — Wicksten 1990b: 595.

Spirontocaris picta . — Rathbun 1904: 101. — Schmitt 1921: 68, fig. 46. — Johnson & Snook 1927: 308, fig. 259e.

Spirontocaris sitchensis . — Rathbun 1904: 102.

Heptacarpus sitchensis . — Holthuis 1947: 13. — Kozloff 1974: 167. — Butler 1980: 22. — Wicksten 1990b: 595. — Wicksten et al. 1996: 71. — Jensen 1995: 47, fig. 80. — Chace 1997: 45. — Stamatious & Jensen 2004: 1. — Kuris et al. 2007: 639, pl. 318 E.

Heptacarpus littoralis Butler, 1980: 221 . — Jensen & Armstrong 1987: 216.

Diagnosis. Rostrum barely exceeding length of antennular peduncle, with 4–8 dorsal teeth, 0–5 ventral teeth. Each segment of antennular peduncle with sharp spine, stylocerite reaching or exceeding end of first segment. Third maxilliped, pereopods 1, 2 with epipods. Pereopods 3–5 stout, with spinose, bifid dactyls. Merus of pereopod 3, with 0–9 spines; pereopod 4, with 0–5 spines; pereopod 5, with 0–5 spines. Pleura of abdominal somites 1–3 rounded, 4, 5 with posterolateral points. Telson with 4 or 5 pairs dorsolateral spines. Male total length 16 mm, female 28 mm.

Color in life. Variable: translucent, striped with brown, white; longitudinally striped with tan along dorsal midline, entirely green, green with white carapace, or nearly black. Changes to pale blue at night.

Habitat and depth. Tide pools, docks, among algae, rocks; mostly intertidal, rarely to 12 m.

Range. Resurrection Bay , Alaska to Yaquina Bay , Oregon ; Duxbury Reef , Marin County, California to Punta Banda, Baja California, Mexico. Type locality Sitka, Alaska .

Remarks. Heptacarpus sitchensis and H. pictus until recently were considered to be separate species on the basis of the epipods. Unlike the former, H. pictus was thought to have epipods on both the first and second pereopods as well as on the third maxillipeds. Some individuals have an epipod only on the left or right first or second pereopod but not on both. Individuals with various arrangements of epipods can be collected in the same tide pool. In the absence of any other distinguishing features, these individuals must be considered to be variants of the same species. Butler (1980) described H. littoralis as a separate species based on its more slender body, larger eye, narrower scaphocerite and long curved propodi on pereopod 3–5. Stamatious & Jensen (2004), by rearing larvae, discovered that H. littoralis is actually a male of H. sitchensis .

Heptacarpus sitchensis , like many other species of carideans, is more active at night.