The shadow barnacle was a silica parasite living on the planet Coruscant. This small crustacean anchored to buildings by feeder roots through which it absorbed nutrients. It retracted into its shell when threatened. The shadow barnacle reproduced by releasing egg seeds and sperm pollen into the air. It consisted of a mouth, pods, and retractable anchor tendrils. It could also move by using its clawed legs, and it had external gill filaments that could be withdrawn into its mouth. They were able to survive the vongforming of Coruscant.