Epialtidae

Epialtidae is a family of marine decapod crustaceans commonly known as spider crabs. This family is classified under the infraorder Brachyura, which comprises true crabs. Epialtidae includes approximately 150 species that inhabit diverse marine environments around the world. Their unique characteristics, including their long, spindly legs and prominent, often spiny carapace, make them easily recognizable and fascinating members of the marine ecosystem.

Depressed Spider Crab – Xenocarcinus depressus

Taliepus marginatus

Spider Crab – Phalangipus hystrix

Pugettia dalli

Pelia pacifica

Hydroid Crab, Arrow Crab, Two-spine Crab – Hyastenus bispinosus

Herbstia camptacantha

Sponge Decorator Crab, Rhinoceros Crab – Hyastenus elatus

Libinia ferreirae

Common Names

Members of the Epialtidae family are often called "spider crabs" due to their elongated legs, resembling those of spiders. Other common names include "stone crabs" and "masked crabs," depending on the specific species and location.

Characteristics

Epialtidae crabs exhibit several distinguishing features that set them apart from other crab families:

  • Elongated Legs: Their most prominent characteristic is their extremely long and spindly legs, significantly longer than their body. These legs are often covered in hair-like setae, which aid in locomotion and camouflage.
  • Spiny Carapace: Epialtidae crabs have a broad, flattened carapace that is often covered in prominent spines or tubercles. These spines serve as protection against predators and may also provide camouflage.
  • Small Abdomens: Their abdomens are small and tucked under their bodies, unlike the more prominent abdomens found in other crab families.
  • Variable Size: The size of Epialtidae crabs can vary significantly depending on the species. Some species are relatively small, while others, like the Japanese spider crab, can reach enormous sizes.

Environments

Epialtidae crabs are found in a wide range of marine environments, including:

  • Coastal Waters: They are commonly found in shallow coastal waters, often associated with rocky reefs, kelp forests, and seagrass beds.
  • Deep Sea: Some species inhabit deeper waters, reaching depths of several hundred meters. These deep-sea Epialtidae crabs are often adapted to the harsh conditions of the deep ocean.
  • Tropical and Temperate Regions: Epialtidae crabs are distributed across tropical and temperate regions worldwide, from the Atlantic Ocean to the Pacific Ocean.

References

For further information on Epialtidae, consult the following resources: