Why do gray whales have parasites on their backs?
A. All whales seem to host other species — although we don’t know for sure if they can really be called parasites. Whale lice tend to be specific for their whales — particular species of these small crustaceans live on particular species of whales. The whale lice are actually kinds of cyamid amphipods. Gray whales have them, humpbacks have them, blue whales too. In the right whale the species are Cyamus ovalis and Cyamus gracilis, in particular, and occasionaly C. ceti, C. erraticus, and C. catadontis. Scientists are not really sure of the function of these “hitchhikers.” They may be eating old skin in a natural cleaning process, or available to clean wounds when needed. They may be taking food from the water that the whales swim through. Other whales, including humpbacks, have barnacles growing on their bodies. Breaching behavior may be a means of knocking this extra weight off their bodies. Q. Do gray whales have any other predators than humans? A. Adult great whales (minke, sei, g
