R. remora and its host seem to partake in a
symbiotic relationship; the common remora does not seem to have a negative overall effect on its host. The host provides the remora with fast-moving water for respiration, a steady flow of food, transportation, and protection. The remora benefits the host by feeding in part on some of its parasites, but increases its hydrodynamic
drag. The common remora's attachment to one host can last for up to three months. During this time, the remora can move its attachment site if it feels threatened. The common remora cannot survive in still water; it needs water flow over its gills to breathe. ==Habitat==