Surface smooth and membranous. Flattened eyestalk pointed and divergent with pigmented cornea mid-dorsally. Antennules and antennae with long, somewhat setose, flagella. Chelipeds unlike and unequal, the larger may be either left or right; surface glossy and compressed, with sharp margins, thin, and slightly curved dorsally. Merus relatively slender with a prominent lobe ventrally. In adult male large cheliped with carpus and hand subequal in length and breadth, but immature male and female with hand longer than carpus. Small hand of male and female has carpus longer than hand and fingers shorter than palm. 1st walking legs flattened, setose and chelate, 2nd also setose with triangular carpus, broad subrectangular propodus and small rounded dactyl. 3rd and 4th walking legs slender with tufts of stiff setae on propodus and dactyl; last leg chelate. Narrow pleura with pubescence on 3rd, 4th and 5th segments. Male with vestigial pleopods on 1st abdominal segment and none on 2nd. Female with egg-carrying uniramous pleopods on 1st segment and biramous on 2nd. Pleopods 3 to 5 are foliaceous and used for backward propulsion. Tail fan with broad flat uropods and subrectangular telson, which is slightly longer than wide and has a tooth on midposterior margin.
Total length: male 115 mm, female 120 mm.
Clear bright colours. Carapace and chelipeds mainly white with patches of yellow, orange, flesh-pink or rose. Walking legs pale pink. Abdomen pink, deep rose and some tinges of yellow. Pleopods white or cream and tail fan often yellow. Eyestalk orange with black cornea. Adult males usually with more white area than females.
Live in burrows excavated in sand or sandy mud in high intertidal. In certain areas tremendous numbers may be found but these are much smaller in size than in areas where the numbers are less. High up on sandy beaches holes about 5 mm in diameter indicate the presence of these animals. Under the surface the burrow widens to about 20 mm and is smoothly plastered with mud and is usually vertical for perhaps 50 cm, then runs horizontal for some distance before rising to the surface again. It is difficult to excavate an entire burrow because the wet sand is so unstable. In highly populated areas collection is relatively simple but in areas where there are fewer and the animals larger and the burrows deeper, much and often fruitless digging is required.
Mutiny Bay, Alaska, to San Diego, California; intertidal.
Distribution In British Columbia
Widespread on sandy beaches of Vancouver Island and the southern mainland. Usually where there is some protection from heavy surf.
Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2019. E-Fauna BC:
Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab
for Advanced Spatial Analysis, Department of Geography, University of British
Columbia, Vancouver. [Accessed:
18/11/2019 4:38:10 PM]
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