360 Shark and Company 



A Remora attached to a Sand shark. 



Courtesy, New York Zoological Society 



The remora's reputation as a ship-holder is based on its abiHty to 

 stick, particularly to sharks. It attaches itself by a kind of suction cup. 

 Its first dorsal fin has modified to form an oval plate on the top of its 

 head. The surface of the plate is ridged, like the sole of a boot. When 

 the remora decides to attach itself to a shark, it merely swims upward 

 so that the disk comes in contact with the shark's belly or side. Then, 

 by muscular action, it raises the ridges and rim of the disk, creating a 

 partial vacuum. 



When the shark feeds, the remora detaches itself by relaxing its disk 

 muscles, and swims off for the crumbs. Then, its meal finished, it re- 

 attaches itself to the shark and awaits its next meal. It can latch on while 

 the shark is moving by the use of tiny barbs on the disk. The barbs 

 act as hooks while the remora gets in position to use its suction mecha- 

 nism. Four or five remoras may attach themselves to a single big shark. 

 Remoras are not true parasites; they do not suck blood or injure the 

 shark, though they are erroneously referred to as sucker fish. Some 

 sharks, however, are infested with hordes of real parasites, ranging in 

 size from the microscopic to the hideous Isopod crustaceans that in- 

 habit the shark's gills, mouth and skin, and are so big that they have 

 parasites. One type of shark parasite is so large, in fact, that Australian 

 aborigines call it "the shark's wife." Some remoras may aid their hosts 

 by feeding on these parasites. 



There are several species of remoras. One {Echeneis naiicrates). 



