Renowned marine biologist Daniel Arauz Naranjo, known for his extensive shark research, encountered a unique sight – an exceptionally rare bright orange nurse shark resembling a Creamsicle in the coastal waters of Costa Rica.
Expressing his astonishment, Naranjo, who heads Costa Rica’s Rescue Center for Endangered Marine Species, described the discovery as unprecedented and astonishing.
Naranjo recently co-authored a scientific paper positing that the distinct coloration of the shark is likely a result of a rare dual genetic mutation. The research findings were recently published in the Marine Biodiversity journal.
Now, the scientific community is intrigued by the possibility of whether this brightly colored shark is a solitary phenomenon or if more of its kind inhabit the Caribbean waters.
Capturing and Releasing the Marvel
Despite his fascination with the orange shark, Naranjo has not had a personal encounter with it.
The remarkable footage and images of the vividly colored shark were captured by a group of sports fishermen off the coast of Costa Rica in August last year.
“We spotted an unusual orange glow beneath the water, which left us in awe,” recounted Garvin Watson, owner of Parismina Domus Dei hotel in Barra del Parismina, as reported by the New York Times.
The fishermen, adhering to catch-and-release practices, documented the peculiar find before releasing the shark back into its habitat and then shared their discovery with local scientists.
Naranjo commended the fishermen for their responsible actions, emphasizing their skill in handling the animals with care and releasing them stress-free.
Nurse sharks, typically ranging from tan to dark brown, are classified as a vulnerable species by the International Union for Conservation of Nature due to various threats like climate change, pollution, habitat loss, and overfishing.
These nocturnal creatures frequent warm, shallow waters where they forage for food such as crustaceans, mollusks, and stingrays during the night. In the daytime, they seek refuge in caves and crevices, as per the Florida Museum of Natural History.
With an average length of 2.4 meters, nurse sharks are known for their gentle demeanor in human interactions.
Rare Genetic Anomalies Unveiled
Following a thorough examination of the footage, Naranjo and his team delved into scientific literature to decipher the mystery behind the orange shark’s unique appearance.
The researchers concluded that the shark likely exhibits two concurrent rare genetic conditions – albinism and xanthism.
Albinism, characterized by the absence of melanin in the skin and eyes, is a rare occurrence but not unprecedented in sharks.
Xanthism, which imparts a yellow or golden hue to animals, has been observed in reptiles and freshwater fish, making this reported case the first instance in a shark, according to Naranjo.
The combination of albinism and xanthism likely accentuates the shark’s bright neon orange coloration, as suggested by Naranjo.
