The
remoras (pronounced or ), sometimes called
suckerfish, are a family (
Echeneidae) of
ray-finned fish in the order
Perciformes. They grow to long, and their distinctive first
dorsal fins take the form of a modified oval, sucker-like organ with slat-like structures that open and close to create suction and take a firm hold against the skin of larger marine animals. By sliding backward, the remora can increase the suction, or it can release itself by swimming forward. Remoras sometimes attach to small boats. They swim well on their own, with a sinuous, or curved, motion.