Scientists Document a Rare Golden Ray in Costa Rica’s Northern Pacific
A small ray the color of a gold coin turned up in shallow water off Guanacaste, and researchers say nothing like it has ever been recorded in its family. The animal was a juvenile female blotched round ray, a common bottom-dwelling species along Costa Rica’s Pacific coast. Rays of this kind are normally sandy brown with dark spots scattered across the disc. This one was a deep, saturated yellow. The condition is called xanthism, and it works in a way that is easier to picture than the name suggests. Ray skin carries different types of pigment cells stacked together. When the cells that produce dark pigment fail to develop, the yellow ones underneath are no longer masked, and the animal comes out gold. The dark spots on this individual survived, which is why researchers describe the case as partial. That detail turned out to matter later. The ray was caught and photographed twice at Playa Manzanillo, near the community of El Jobo in La Cruz, during a monitoring program run...