In a scientific first, researchers have tagged wild smalleye stingrays, the world’s largest and rarest marine stingray, in Mozambique. These monstrous Pacific Ocean fish, which can reach up to 10 feet long, are so rarely seen, they’re likely a critically endangered species.

After weeks of surveying the coast off the Bazaruto Archipelago, National Geographic Explorer and ray expert Andrea Marshall finally spotted a smalleye in shallow water. She dove in, and, with a six-foot-long pole, lightly touched the animal, taking a small skin sample from its underside. The fish remained calm, which was a good sign: Smalleyes have a stinging spine the length of a human forearm. Any wrong move “would put us