Galatheidae

Galatheidae is a family of decapod crustaceans commonly known as squat lobsters or “spider crabs.” These are marine invertebrates found in a wide range of habitats, from shallow coastal areas to the deep ocean. They are characterized by their distinctive squat, flattened bodies, long legs, and the absence of a rostrum, which is a pointed projection on the carapace (upper shell).

Galathea dispersa

Galathea bolivari

Squat Lobster – Galathea aequata

Twin-spotted Squat Lobster – Galathea bimaculata

Squat Lobster – Galathea tanegashimae

Galathea subsquamata

Crinoid Squat Lobster, Feather Star Squat Lobster, Elegant Squat Lobster, Elegant Crinoid Squat Lobster – Allogalathea elegans

Baba’s Crinoid Squat Lobster – Allogalathea babai

Common Names

Members of the Galatheidae family are commonly referred to as squat lobsters or "spider crabs." The term "spider crab" is also used for other crustaceans, particularly those in the family Majidae, which are true crabs. However, squat lobsters share some similarities with true crabs, including their flattened bodies and long legs, which contribute to their common name.

Characteristics

Galatheidae are typically characterized by the following features:

  • Squat, flattened body: Their bodies are dorsoventrally compressed, meaning they are flattened from top to bottom, which is characteristic of squat lobsters.
  • Long legs: They have long, slender legs that are often covered in setae (bristles), which can aid in locomotion and food capture.
  • Absence of rostrum: Unlike many other crabs, squat lobsters lack a rostrum, the pointed projection on the carapace.
  • Eyes on stalks: They have stalked eyes, which are located on movable stalks that allow for wider visual range.
  • Chelipeds: Their first pair of legs are modified into chelipeds (pincers), used for defense and catching prey.
  • Abdomen: Unlike true crabs, the abdomen of squat lobsters is visible and folded beneath the carapace.
  • Size: Squat lobsters vary in size, with some species being quite small while others can reach considerable lengths.

Environments

Galatheidae are found in a wide range of marine habitats, including:

  • Shallow coastal waters: Many squat lobsters live in relatively shallow waters along coastlines, where they often burrow in sediments or hide among rocks.
  • Deep sea: Several species of squat lobsters inhabit the deep sea, where they are adapted to the cold, dark, and high-pressure conditions.
  • Coral reefs: Some species are associated with coral reefs, where they may feed on sponges, algae, or small invertebrates.

References

For further information on Galatheidae, refer to the following sources: