Cameras attached to whales to study their behaviour have also revealed that the remora fish that ride along with them prefer to stay behind the whale’s blowhole to limit drag
Source:
https://www.newscientist.com/article/2258565-suckerfish-use-fast-flowing-water-to-surf-across-swimming-whales-skin/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home