From Natural History of Southeast Alaska
Purple shore crab (Hemigrapsus nudus), except that it often lives lower in the intertidal area and in calmer spots, is generally somewhat smaller, and is usually greenish as opposed to purplish, without purple spots on the claws.
For positive identification, such as of strange color variants or bleached molts, look at the legs: those of Purple shore crab (Hemigrapsus nudus) are distinctly less hairy, if they have any hair at all.
- Invertebrate Zoology at Friday Harbor Laboratory page for Hemigrapsus oregonensis Color variation in Hemigrapsus oregonensis (Arthropoda, Pancrustacea, Malacostraca, Brachyura)
- WoRMS Page for Hemigrapsus oregonensis
- Search Arctos Database for Hemigrapsus oregonensis (Southeast only)
- Search Arctos Database for Hemigrapsus oregonensis (entire database)
- Encyclopedia of Life search for Hemigrapsus oregonensis
- iNaturalist Observations for Hemigrapsus oregonensis in Southeast Alaska