Scyra acutifrons Dana, 1851
Common name(s): Sharp-nosed crab
Infraorder Brachyura (true crabs)
|A male Scyra acutifrons from Swirl Rocks, WA. Carapace width about 12 cm.|
|(Photo by: Dave Cowles, July 2000)|
How to Distinguish from Similar Species: Oregonia bifurca and Hyas lyratus have a lyre-shaped body and a toothed expansion of the carapace on both sides of the anterior half, plus the rostrum is widest at the base. Pugettia gracilis, Pugettia producta, and Pugettia richii have a sharp projection to the side near the middle of the carapace.
Geographical Range: Kodiak, Alaska to Punta San Carlos, Mexico. Uncommon south of Monterey Bay, CA
Depth Range: Mostly subtidal, to 220 m
Habitat: Rocky areas, especially around boulders densely covered with invertebrates. Sometimes found on pilings.
Biology/Natural History: Feeds on detritus
and sessile invertebrates. Predators include rockfish (Sebastes
atrovirens, S. chrysomelas and S. caurinus), kelp greenling
decagrammus, and sculpins. Seems to be often found around
sea anemones. May decorate slightly by putting a few pieces of algae
on its rostrum. Other algae and bryozoans seem to overgrow the carapace
naturally. This crab often sits with the anterior end pointed down.
Females may carry eggs nearly any time of year. May reproduce several
times a year. This species has a terminal molt so full-grown adults
will no longer grow (and the carapace
can become overgrown with organisms)
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Morris et al., 1980
This individual is hiding under a subtidal rock near Rosario. Underwater photo by Jim Nestler, July 2005
A view of another individual, captured between 100-120 m depth in the San Juan Channel. Photo by Dave Cowles, August 2015.
A view of the underside. Photo by Dave Cowles, August 2015