The Spearfish remora, Remora brachyptera, is a remora of the family Echeneidae, found circumglobally in tropical and subtropical seas. Its length is up to (50 cm).
The spearfish remora is an elongate round-bodied fish, with a large oval suction disc on top of the head. This disc is actually a highly modified first dorsal fin with a raised flattened edge that acts as a seal, and a series of horizontal septae that can be moved so as to create a vacuum in a sealed chamber. Using this device spearfish remora can attach themselves to the skin of a variety of large host species, including sharks, groupers, rays, turtles, whales, and even the underside of ships. This puts them in an ideal location to feed on the small scraps left over from the feeding activities of the host and also gives them some protection from other predators. It is also possible that the spearfish remora gets some of its food by removing parasites from the body of its host.
Spearfish remora are variable in color ranging from a uniform pale grey to almost black.
Illustration by Dr Tony Ayling