Sharks don't need dating apps—the males just follow their noses. Stream the #SharkFest collection on Disney and Hulu. | National Geographic TV

Female sharks can have a tough time during the mating season. That could not be more evident than in this video of a blue shark as it swam past an Atlantic Shark Institute boat in waters off the RI coast. This video, shot by Dr. Josh Moyer, shows a significant number of bite marks made by males to hold the female in place during mating. These scars often lead us to an early indication of what sex the shark might be, before we can confirm it for reaearch purposes.#shark #sharks #sharkresearch | T