What Makes Hermit Crabs Unique?

Hermit Crabs Unique Characteristics

Final Answer: Hermit crabs, as crustaceans, possess unique characteristics like a cephalothorax, biramous appendages, and a chitinous exoskeleton. Their exoskeleton is often infused with calcium carbonate for increased strength. Some hermit crabs have a mutualistic relationship with sea anemones.

Explanation:

Hermit crabs are unique due to have a number of distinctive characteristics. They are a species of crustacean, and possess two pairs of antennae, mandibles as mouthparts, and biramous appendages, meaning their legs are split into two parts known as endopods and exopods. Most crustaceans, including hermit crabs, have fused their head and thorax to form a cephalothorax which is covered by a plate called the carapace. Hermit crabs have a chitinous exoskeleton that is frequently shed during their growth and development. In many aquatic species, this exoskeleton is infused with calcium carbonate, enhancing its strength. Hermit crabs have an open circulatory system where blood is pumped into the hemocoel by the dorsally located heart. Respiratory pigments used include both hemocyanin and in a few species, hemoglobin. Interestingly, some hermit crabs establish a mutualistic relationship with sea anemones. The crab brings the anemone food particles from its prey, getting in return protection from predators thanks to the anemone's stinging cells.