Goose barnacle anatomy, artwork. Goose barnacles are hermaphrodite filter-feeding crustaceans that attach themselves to rocks and other surfaces in intertidal zones. They attach via the peduncle (stalk, dark grey at left) using cement that is produced by a cement gland (yellow, right) in the main body of the barnacle. The peduncle also contains the ovaries. The mantle houses the majority of the barnacle, including the testicle, mouth and stomach, and is covered in calcerous plates (white). The grey strands at top are cirri, which extend out of the shell for feeding.