Remora

Remora, warmwater fish (family Echeneidae) that feeds off other marine animals. A remora uses an oval disc at the top of its head as a suction cup to attach itself to a host animal—usually a shark, whale, sea turtle, or other large marine animal—and is carried along with them as they swim. Ranging 7 in (17 cm) to 3.5 ft (110 cm) in length, remoras enjoy a symbiotic relationship with the animals they attach themselves to, eating leftover scraps of food not eaten by the hosts while removing parasites from the hosts. Some remoras cling to the hulls of ships and boats.