''Glebocarcinus oregonensis'', commonly known as the pygmy rock crab, is a species of

crab Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...

found on the Pacific coast of

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

Description

It is usually red/brown but this may vary; their legs have many setae (hairs). The

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

reaches a width of about , and is widest at the 7th or 8th lateral tooth. 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.

Ecology

''Glebocarcinus oregonensis'' is found mostly in crevices, holes (dead barnacles) and under rocks. They can live in depths of up to . They are nocturnal feeders, feeding mostly on small

barnacle A barnacle is a type of arthropod constituting the subclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in eros ...

s, snails,

bivalves Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...

, worms,

green algae The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as ...

and Pacific oysters. Predators include Pacific cod, river otters and red rock crab.

Breeding Breeding is sexual reproduction that produces offspring, usually animals or plants. It can only occur between a male and a female animal or plant. Breeding may refer to: * Animal husbandry, through selected specimens such as dogs, horses, and rab ...

occurs during the summer, and the Puget Sound females carry eggs from November to May. It is not unusual to find harems consisting of one male with as many as seven females. Males may carry females that are molting and continue until their new shell hardens, for mating occurs after females molt.

Description

Ecology

References

Further reading