barnacle biology

Barnacles are crustaceans related to crabs and shrimp. They begin life as free-swimming larvae that settle onto surfaces like rocks, ships, or marine structures. Once attached, they secrete a strong, calcium carbonate shell, forming a hard, protective outer layer. Barnacles are filter feeders, using specialized appendages called cirri to scoop plankton and small particles from the water. They are sessile as adults, meaning they stay fixed in one spot, but their shells can accumulate over time, sometimes causing issues like increased drag on ships. Barnacles play roles in marine ecosystems and biofouling processes.