Costa Rica’s rich seas surprised the world last week with a unique discovery: the first nurse shark with xanthochromism ever documented. News spread quickly after pictures were released, but the encounter actually happened on August 10, 2024, when local anglers in the Caribbean waters of Costa Rica came across this extraordinary sight.
The shark was spotted during a sportfishing trip near Tortuguero National Park. The event made national and international headlines after a scientific paper was published earlier this month titled “First record case of free-living xanthism in the nurse shark Ginglymostoma cirratum from Caribbean Sea.”
The shark, about two meters long, displayed intense yellow-orange pigmentation, a condition called xanthochromism. Even more remarkable, it also had bright white eyes, meaning it was albino as well. These conditions are extremely rare in marine species, and this case is not only the first documented in nurse sharks worldwide, but also the first ever recorded in a Caribbean cartilaginous fish.
Scientists have long thought that the brown tones of nurse sharks are essential for survival, helping them blend into their surroundings and making them less visible to predators. Yet finding an adult shark with such striking colors shows that survival can take many forms, and that nature often finds its own way.
The shark was safely released, and scientists studied it through photographs, considering possible causes for the unusual coloration. Genetic variation or environmental factors, such as rising ocean temperatures, could be responsible.
This is one of those moments when nature surprises us in the most unexpected ways, but the fact that it happened in Costa Rican waters reminds us of the richness of this country and how fortunate we are to live surrounded by such natural wonders.