Sharks are known for their sleek, predatory nature, but every once in a while, nature surprises us with a twist. In a rare and stunning occurrence, a nurse shark was caught off the coast of Costa Rica in August 2024, sporting a vibrant orange hue that made it stand out like a traffic cone in the ocean.
This particular nurse shark, scientifically known as Ginglymostoma cirratum, exhibited a unique combination of abnormal pigmentation. It displayed both albinism, a lack of dark pigmentation, and xanthism, an excess of yellow pigmentation. This rare condition, known as albino-xanthochromism, resulted in the shark’s striking orange coloration, coupled with white eyes.
Despite its unusual appearance, the shark seemed to be thriving in its natural habitat in the warm waters of the Caribbean Sea. The encounter with this mango-colored marvel took place near Tortuguero National Park, where a fisherman named Juan Pablo hooked the shark at a depth of 37 meters. After capturing several photographs and taking measurements, the shark was released unharmed back into the sea.
Upon further investigation by marine biologists from the Federal University of Rio Grande in Brazil, led by Marioxis Macías‑Cuyare, the shark’s condition was diagnosed as albino-xanthochromism. This double genetic quirk has been rarely documented in nature, with previous cases mainly observed in birds. However, a few instances have also been reported in marine species, such as a speckled hind and a spotted ray.
Surprisingly, the bright coloration did not seem to hinder the shark’s development, as it was measured to be 200 centimeters in length, indicating full maturity. This process typically takes at least a decade for nurse sharks to reach. Abnormal coloration in marine species is often attributed to genetic mutations, highlighting the diverse and fascinating adaptations that can occur in the underwater world.
While other cases of unusual pigmentation have been observed in nurse sharks, including albinism, piebaldism, and hypomelanosis, this particular individual represents the first documented case of albino-xanthochromism. The researchers suggest that environmental factors may also influence such genetic traits and recommend further investigation into the regional population’s genetic variability.
The findings of this study were published in the journal Marine Biodiversity, shedding light on the need for continued research to understand how environmental conditions impact the expression of genetic traits in marine species. The striking orange nurse shark serves as a reminder of the wonders of nature and the endless possibilities for discovery in the depths of the ocean.
