span class="large"stronguRemoras/u/strong. Worldwide, and virtually always in the Revillagigedos, Mantas tend to have “hitchhikers,” called Remoras or “suckerfish.” While there are many different species of Remoras, the ones found on these Mantas are quite large, some almost 3 feet long. On the top of a Remora’s head, what would otherwise be a dorsal fin has been modified into a disk-shaped surface, with small barbs on its edges. The Remora will initially use the barbs to attach to a host animal; and, once the fish has attached, it raises the rim of the disk to create a a href="http://www.geocities.com/museumcataloging/remora.html"; target="_blank"powerful vacuum between it and the host/a. em /emInterestingly, though Remoras hang on with a remarkably powerful suction, they can release instantly, when they want. When a diver approaches a Manta, the Remoras will generally move immediately away from the diver, often to the underside of its host./spanbr/span class="large" /spanbr/span class="large"emRemoras are not parasites/em and do not harm their hosts. Instead, the commensal relationship appears to be one in which the Remora benefits in several ways, while a href="http://animaldiversity.ummz.umich.edu/site/accounts/information/Remora_remora.html"; target="_blank"the host is neither harmed nor helped/a. /spanbr/span class="large"The Remora benefits by getting a free ride through open water and by the protection from predators it enjoys by being associated with a larger animal. In addition, it benefits from eating whatever a href="http://www.geocities.com/museumcataloging/remora.html"; target="_blank"scraps /a/spanspan class="large"a href="http://www.geocities.com/museumcataloging/remora.html"; target="_blank"are left over from the host’s meals/a. Some Remora species also act as “cleaner fish,” eating small parasites and dead skin on the host’s body. While this is a clear benefit for the Remora, a href="http://animaldiversity.ummz.umich.edu/site/accounts/information/Remora_remora.html"; target="_blank"it is not clear whether the host actually benefits/a from this behavior. Regardless whether the relationship is a purely neutral commensal relationship for the Manta, it would appear that the Manta (and other Remora host animals) are physically unable to catch their guests or otherwise rid themselves of them./span