Last summer, a fisherman in Maine hauled in a 1-in-50-million catch: a half brown and half red lobster. All lobster shells contain pigments that can appear red, yellow, or blue, says Michael Tlusty, a biologist at the University of Massachusetts Boston. Usually, these colored compounds mix together to give lobsters brown shells. But sometimes rare mutations change the animals’ DNA—a molecule that carries hereditary information. That can create unusual pigment patterns. The recently caught two-toned lobster now lives with other colorful crustaceans—one all-blue and two spotted lobsters—at the Maine Center for Coastal Fisheries.