Common Remora

The common remora (Remora remora) is a ray-finned fish of the family Echeneidae in the order Carangiformes, growing 30 to 110 centimeters long depending on the species. Its most distinctive feature is a modified first dorsal fin that forms an oval, sucker-like disc on top of its head, made of stout, flexible membranes with slat-like structures that open and close to create suction. It is a tropical open-ocean fish that spends most of its life attached by this disc to a host animal such as a whale, turtle, shark, or ray, occasionally appearing in temperate or coastal waters when its host migrates there; it detaches by swimming forward or increases suction by sliding backward. The relationship is often mutualistic, with the remora removing parasites and shed skin from its host while gaining protection and a free ride. It spawns in June and July in the mid-Atlantic and in August and September in the Mediterranean.