Glebocarcinus oregonensis, commonly known as the pygmy rock crab, is a species of crab found on the Pacific coast of North America.
It is usually red/brown but this may vary; their legs have many setae (hairs). The carapace reaches a width of about 5cm (02inches), and is widest at the 7th or 8th lateral tooth.[1] The chelipeds are black at the tip, and the dactylus of the cheliped has no spiny ridges; the dorsal surface is covered with small tubercles (rounded projections), and males have larger chelipeds than females.
Glebocarcinus oregonensis is found mostly in crevices, holes (dead barnacles) and under rocks.[2] They can live in depths of up to .[1] They are nocturnal feeders, feeding mostly on small barnacles, snails, bivalves, worms, green algae and Pacific oysters.[2] Predators include Pacific cod, river otters and red rock crab.[2]
Breeding occurs during the summer, and the Puget Sound females carry eggs from November to May.[2] It is not unusual to find harems consisting of one male with as many as seven females.[2] Males may carry females that are molting and continue until their new shell hardens, for mating occurs after females molt.[2]