Arthropoda · arthropods

Red king crab

Paralithodes camtschaticus

Lithodidae · king crabsIUCN: Not evaluated
Red king crab
Photo: Dr. Roger Mann, VIMS · Public domain · Wikimedia Commons · resized

The largest king crab, made famous by the Bering Sea fishery.

Fun factDespite the name, king crabs are more closely related to hermit crabs than to true crabs.

Waters
Arctic Ocean, North Pacific
Depth zone
Continental shelf
Diet
Clams, urchins & worms
Size
Leg span up to 1.8 m

Classification

Arthropoda › Malacostraca › Decapoda › Lithodidae

  1. Kingdom Animalia animals
    • Many-celled organisms that eat other living things for energy (heterotrophs)
    • Cells have no cell walls
    • Most can move at some stage of life
  2. Clade Bilateria bilateral animals
    • Body has a left and right side that mirror each other (bilateral symmetry)
    • Head end with concentrated nerves; three tissue layers
    • Includes about 99% of all living animal species
  3. Clade Protostomia protostomes
    • In the embryo, the first opening usually becomes the mouth
    • Main nerve cord runs along the belly (ventral)
    • Includes mollusks, worms, and arthropods
  4. Clade Ecdysozoa molting animals
    • Grow by shedding their outer layer (molting, ecdysis)
    • No cilia used for movement
    • Includes arthropods and nematode worms
  5. Phylum Arthropoda arthropods
    • Hard outer skeleton made of chitin (exoskeleton)
    • Jointed legs and a segmented body
    • The largest animal phylum by species count
  6. Subphylum Crustacea crustaceans
    • Two pairs of antennae
    • Branched (biramous) legs in many species
    • Most breathe with gills
  7. Class Malacostraca crabs, shrimp & kin
    • Body of a head, 8-segment thorax, and 6-segment abdomen
    • Includes crabs, shrimp, lobsters, krill, and isopods
  8. Order Decapoda ten-legged crustaceans
    • Ten walking legs, the first pair often with claws
    • Shell covers head and thorax together (carapace)
  9. Suborder Pleocyemata egg-brooding decapods
    • Females carry their eggs under the abdomen until they hatch
    • Includes true crabs, lobsters, and most shrimp
  10. Infraorder Anomura hermit & king crabs
    • Last pair of walking legs is small and often hidden
    • Includes hermit crabs, king crabs, and mole crabs
  11. Family Lithodidae king crabs
    • King crabs: only three pairs of walking legs visible
    • Evolved from hermit crab ancestors
  12. Genus Paralithodes
    • Species in the same genus are very close relatives and often look alike.
  13. Species Paralithodes camtschaticus Red king crab

Closest relatives in the guide