Overview

• The peer-reviewed description in Marine Biodiversity details a roughly 2-meter nurse shark photographed and released after a sport fishing catch near Tortuguero National Park in August 2024.
• It is the first documented instance of xanthism in this species and the first recorded case in cartilaginous fishes in the Caribbean, according to the study.
• Photos show intense yellow-orange pigmentation and white eyes without visible irises, leading authors to suggest a rare albino‑xanthochromism presentation.
• The shark’s adult size led researchers to infer no obvious survival cost, though conspicuous coloring can increase visibility to predators and potentially affect foraging.
• Authors say the pigmentation likely has a genetic basis but note possible influences from inbreeding, environmental stress, elevated temperatures, or hormonal factors, and they credit anglers’ images and a local tour company’s Facebook post for enabling the documentation.