Learn About Crabs & Relatives

Crabs represent a hugely diverse group including brachyuran crabs, porcelain crabs, lithode crabs, squat lobsters, hermit crabs, and so on.  For convenience, they are considered in this single section in the ODYSSEY.  Much more work has been done on brachyuran crabs (Dungeness crabs, rock crabs, shore crabs) than on all of the rest of the groups combined.

NOTE  references to “crabbe”, “crabban”, and “crabben” are common in English literature dating from as early as the 11th C., doubtless because of their good taste and commercial value.  Crabs along with shrimps, hermit crabs, lobsters, and crayfishes are classified in the Order Decapoda in the Subphylum Crustacea

NOTE  most applied research on crabs on this coast focuses on Dungeness crabs Metacarcinus magister (formerly Cancer magister)  While many studies on this species are included in the ODYSSEY, a huge volume of commercial- and fisheries-oriented research papers is left out. As one example, the California Department of Fish and Game’s excellent Dungeness Crab Research Program (1974-80), published in an entire journal volume, is omitted (Life history, environment, and mariculture studies of the Dungeness crab, Cancer magister, with emphasis on the Central California Fishery Resource, Wild & Tasto, eds. 1983 Calif Fish Bull 172 pp. 1-352). Note that most references to Cancer magister in the ODYSSEY have now been changed to Metacarcinus magister. In retrospect, his may not have been a good idea, for reasons of the confusion it is likely to generate in attempting to use the indexing system. So, when searching for papers dealing with Dungeness crabs, do searches using each genus name. This last applies also to the cancrid species listed below whose scientific names have recently been changed.

Other common west-coast cancroid crabs with new genus or species names are:

Cancer oregonensis, now changed to Glebocarcinus oregonensis
Cancer antennarius, now changed to Romaleon antennarium
Cancer anthonyi, now changed to Metacarcinus anthonyi
Cancer gracilis, now changed to Metacarcinus gracilis

In fact, of the 6 most common west-coast cancrid species, only Cancer productus has (for now) remained unchanged

ANIMATION of snail meeting CRAB
© 2010 Thomas Carefoot

To learn about west-coast CRAB: select a topic from the Crustacea > Crabs & relatives menu at the top of the page

OR: play the ANIMATION of the snail meeting the CRAB

OR, if you want to see other animations: follow the snail on its ODYSSEY by CLICKING on any X-marked invertebrate on the map

Phylum Arthpropods (lit. “soft” or “shellfish” L.)

Subphylum Crustacea (lit. “crust or rind” L.), referring to the hard calcified exoskeleton

Class Malacostraca includes all the “advanced” crustaceans

Order Decapoda (lit. “ten feet” G.);  however, in all groups at least one of the 5 pairs of walking appendages is modified into claws, and in some groups (e.g., lithode crabs and hermit crabs) the 5th pair is modified or lost

Suborder Pleocyemata

Infraorder Brachyura including the so-called “true” crabs (represented on the west coast of NA by more than 3 dozen common species)

Infraorder Anomura including porcelain, lithode, galatheid, mole, sand, and hermit crabs