Remoras are pretty weird fish, but a new study shows they really have no boundaries when it comes to mooching off their manta ray hosts. These tropical suckerfish are best known for hitching a ride on sharks, whales, and even turtles. They grab on to their host with a sucker on the back of their head, which is actually a modified dorsal fin. This allows them to travel much further than they ever would otherwise, while getting a nice flow of oxygenated water across their gills, and food scraps