Miracle Orange Shark Emerges in Costa Rica Waters An Unseen Color Mutation Baffles Scientists
Off Costa Rica’s Caribbean coast, a nurse shark arrived in an orange hue—unlike its usual brown cookie-dough color—and with white eyes staring from a pale face. This is the story of a miracle color mutation never before seen in this species, turning a routine catch into a headline about nature’s surprises.
In This Article:
Discovery and Description of a Stunning Orange Nurse Shark
On 10 August 2024, off the coast of Costa Rica near Tortuguero National Park, the mango menace was hooked at a depth of 37 meters by fisherman Juan Pablo. He snapped several photographs and took its measurements before releasing it unharmed. The photos were later posted on social media by eco-tourism company Parismina Domus Day. Intrigued, marine biologists led by Marioxis Macías‑Cuyare of the Federal University of Rio Grande in Brazil got in touch with the fishers and, with the information provided, diagnosed the shark's strange hue. "The shark exhibited an intense, uniform yellow to orange coloration and white eyes, with no visible iris," they wrote in their report, published in August 2025. "The presence of white eyes, particularly the lack of the typically black iris (Fig. 1d), suggests that the specimen was most likely displaying an abnormal condition known as albino-xanthochromism, rather than xanthism alone."
A Rare Double Mutation Spotted in the Ocean
While extremely rare, this double quirk of genetics has been documented in nature, mostly in birds. However, it has also been spotted in the oceans. A speckled hind (Epinephelus drummondhayi) caught off the coast of North Carolina in the Gulf of Mexico was diagnosed with albino-xanthochromism in 1978; and a bulletin describing an albino-xanthochromic spotted ray (Raja montagui) from the Irish Sea was published in 2018.
Size and Maturity of the Tangerine Terror
One glance at the specimen’s size tells the story: 200 centimeters (2.0 meters) from nose to tail-tip, indicating full maturity—a process that usually takes at least a decade for this species. One might think such bright coloration would hinder a shark's lifestyle, but the fisher's measurements showed that this was not the case.
Environmental Questions and Potential Trends
"Is this an isolated case? Could it represent an emerging genetic trend within the regional population? Is it related to specific environmental factors in the northern Caribbean of Costa Rica, or does it reflect the natural genetic variability of the species and its capacity to adapt to changing environments?" they wrote. "Addressing these questions highlights the need for further investigation into how local environmental conditions influence the expression of such genetic traits."
Documentation and Publication
Their analysis was published in Marine Biodiversity.
