ABOVE: Chelonibia testudinaria barnacle on turtle shell © INATURALIST.COM, QUENTIN GROOM
Almost by definition, barnacles are immobile: these crustaceans cluster on surfaces such as whale heads, sea turtle shells, coastal rocks, and ship hulls. Once barnacle larvae mature, they travel on ocean currents in search of an anchoring place, preferentially settling in locations with good water flow, which often happen to be moving marine animals. Barnacles stick to host locations by secreting an adhesive cement, typically from a rigid plate on their undersides, that glues them to the surface. The general consensus has long been that barnacles then remain permanently cemented to their chosen surfaces, never to move again.
But a 2008 paper described an exception in barnacle immobility in the turtle barnacle Chelonibia testudinaria. This unexpected observation inspired John Zardus, a marine biologist and professor at The Citadel in South Carolina, and his colleagues to investigate barnacle locomotion on ...
