The shark’s white eyes indicate a potential form of albinism, a condition involving a lack of melanin pigmentation.
A rare and visually striking shark has been spotted off the coast of Costa Rica, drawing widespread interest from marine biologists and the public alike. The unique nurse shark, notable for its vibrant orange colouration and white eyes, was encountered by fisherman Garvin Watson near Tortuguero National Park in August 2024.
The shark was observed at a depth of 37 meters, in waters with a temperature of 31.2°C. “[It was] incredible,” Watson told USA Today. “We couldn’t believe what we had in front of us, an orange shark that looked like an alien.” He took photographs of the unusual marine animal before releasing it back into the ocean. Watson and his companions later described the encounter to marine researchers, comparing the shark’s colour to that of a goldfish.
Though Watson had initially shared photos of the shark on his Facebook page last year, public fascination surged following the release of a recent scientific study titled “First record case of free-living xanthism in the nurse shark Ginglymostoma cirratum (Bonnaterre, 1788) from the Caribbean Sea.”
The 6-foot, 6-inch nurse shark has become a subject of scientific curiosity due to its distinctive pigmentation. According to marine biologists, the shark’s vivid orange hue is the result of a rare genetic condition known as xanthism, which causes yellow or golden pigmentation in an animal’s skin, scales, or fur. Xanthism is extremely uncommon and has been previously documented in some species of fish, reptiles, and birds, but not in this particular shark species, until now.
The peer-reviewed study, published this month in the journal Marine Biodiversity, was authored by Marioxis Macías-Cuyare, Gilberto Rafael Borges Guzmán, and Daniel Arauz-Naranjo. The researchers wrote that the shark represents “the first scientifically documented case of total xanthism in the species and the first record from the Caribbean Sea.”
In addition to xanthism, the shark’s white eyes indicate a potential form of albinism, a condition involving a lack of melanin pigmentation.