A giant shark was reeled in during a sport fishing trip in Costa Rica that is being hailed as a first-of-its-kind catch.
The six-and-a-half-foot-long shark exhibited xanthism, a rare pigmentation condition that causes an excess of yellow or golden tones in the skin, scales or fur of animals.
While xanthism has been observed in a few fish species, it has never before been documented in cartilaginous fish, a group that includes sharks, rays, and skates, in the Caribbean.
In addition to xanthism, the shark also showed albinism, which explained its striking white eyes.
Typically, nurse sharks have light to dark brown skin, which helps them blend into reefs and rocky seafloor habitats where they spend most of their time hunting.
‘The discovery of a yellow nurse shark raises important questions about the genetics and adaptability of nurse sharks,’ the study said.
‘Is this a one-time occurrence, or could it signal a new genetic trend in the local population?’
Based on the shark’s size, researchers from the Federal University of Rio Grande concluded that this unusual pigmentation did not appear to affect its survival.
Anglers were on a sport fishing trip when they pulled in a stunning orange shark
Scientists analyzed images of the catch, conducing the shark exhibited xanthism, a rare pigmentation condition that causes an excess of yellow or golden tones in the skin, scales or fur of animals
Xanthism is considered extremely rare across the animal kingdom. It has been recorded in a few species of fish, reptiles, and birds, but confirmed cases remain limited.
In freshwater fish such as guppies, cichlids, and even goldfish, the condition sometimes produces striking yellow morphs.
Certain birds, like parrots and canaries, have also displayed golden plumage linked to xanthism, while occasional reports in reptiles describe unusually yellow snakes or lizards.
Because this coloring makes animals more visible, scientists believe xanthism often lowers survival rates in the wild.
Albinism, though slightly better known, is also uncommon and can pose serious challenges to animals that develop it.
The absence of melanin results in pale skin, scales, or fur, along with white or red eyes. In the wild, this lack of natural camouflage can make albino animals easier targets for predators and less effective hunters.
The condition may also increase sensitivity to sunlight and, in some cases, reduce the likelihood of finding a mate.
For this reason, the fact that a nurse shark showing both xanthism and albinism survived into adulthood makes the discovery especially significant.
The shark also had white eyes due to albinism
While the conditions usually hinder survival, scientists said the shark’s size suggests it is thriving
The survival of this vividly colored shark into adulthood also offers a rare glimpse into the adaptability of the species and raises new questions for marine biologists about genetic diversity in Caribbean nurse shark populations.
Nurse sharks are benthic predators, meaning they spend most of their time on or near the seafloor, often around reefs and rocky areas.
Their typical brownish coloring helps them blend in with the surroundings, making them harder to spot.
This shark’s bright yellow-orange color, however, would have made it stand out, which makes its survival into adulthood particularly remarkable.
It is unclear whether this unusual coloring offers any advantages or if the shark simply managed to thrive despite being more visible.
