The tropical islands of the Florida Keys between the Atlantic Ocean and the Gulf of Mexico are a remarkable habitat with enormous biodiversity. The sea in which the islands are located is also home to many animals and corals that cannot be found anywhere else in the world. One of these animals is a bright yellow sea snail that researchers recently discovered there. In honor of “Margaritaville,” a fictional place in Florida from a song by Jimmy Buffett, the team led by Rüdiger Bieler from the Fields Museum in Chicago named the mollusc species the “Margarita snail” (Cayo margarita).
But the lemon-colored snail isn’t the only new discovery in the Caribbean: It has a lime green cousin (Cayo galbinus), named for its “greenish-yellow” color, which the same team recently discovered in the Caribbean Sea in Belize. Because different colors are not uncommon in snails, the researchers initially thought they were the same species. However, sequencing their DNA revealed that although they are externally similar, they are genetically different. Together, the two snails are now assigned to the new genus “Cayo,” after the Spanish word for small, flat island.
The genus of snails belongs to the family of “worm snails” that spend most of their lives in the same place, preferably on dead corals. “Once the young animals have found a suitable place to live, they stick their shells to the ground and never move away again,” explains Bieler. The snail’s shell then grows as an irregular tube around the body. To hunt, the animal spreads a mucous net with which it catches plankton. The mucus also contains antibodies that are supposed to keep other sea creatures away. The discoverers suspect that the bright color of the snails also serves as a deterrent.
Despite decades of research into marine life in the tropics, the two snails have only now been discovered. Although they live in shallow waters where many tourists snorkel, they are very small and, despite their color, live so well hidden that they have simply been overlooked until now.