Majidae

The Majidae are a family of crabs that are known for their diverse morphology and wide distribution in marine environments. This family, belonging to the infraorder Brachyura, encompasses a broad range of species, many of which are commonly known as spider crabs, due to their long, spindly legs. Majidae are characterized by their unique adaptations, including the ability to camouflage themselves with algae and other marine organisms, making them a fascinating and diverse group of crustaceans.

Lesser Spider Crab – Maja crispata

Maja brachydactyla

European Spider Crab, Spiny Spider Crab, Spinous Spider Crab – Maja squinado

Common Names

Majidae crabs are commonly known as spider crabs due to their long, slender legs, which resemble those of spiders. Other common names include stone crabs, decorator crabs, and kelp crabs, reflecting the habitats and characteristics of specific species.

Characteristics

Majidae crabs exhibit a wide range of morphological features, but some key characteristics define the family:

  • Long, Slender Legs: Majidae crabs are easily identified by their long, spindly legs, often much longer than their body. These legs are primarily used for walking and scavenging.
  • Spiny Carapace: The carapace, or shell, of Majidae crabs is typically covered with spines or tubercles. These structures provide protection and camouflage.
  • Camouflage: Many Majidae crabs are known for their ability to camouflage themselves with algae, sponges, and other marine organisms. They attach these materials to their bodies, blending seamlessly with their surroundings.
  • Variable Size: The size of Majidae crabs can vary greatly, depending on the species. Some species are relatively small, while others can reach considerable sizes, with leg spans exceeding several feet.

Environments

Majidae crabs are found in a wide range of marine environments, from shallow coastal waters to deep sea habitats. They are commonly found on rocky shores, coral reefs, kelp forests, and seagrass beds. Their adaptability allows them to thrive in diverse ecosystems, playing an important role in the food web.

References

For more information about Majidae crabs, you can refer to these resources: