‘Incredible.’ Mangled shark off Florida took just months to regrow fin, study says
Mariners have long credited sharks with having seemingly “superhero”-like capabilities.
Now a newly released study has concluded one of those powers may be the ability to regenerate mangled body parts.
The research, published Dec. 14 in the Journal of Marine Sciences, focused on the case of a badly injured silky shark seen off the coast of Jupiter, Florida.
It was estimated more than 20% of the shark’s dorsal fin had been mysteriously ripped away, the study notes.
Then something “incredible” happened.
“The shark was photographed 332 days after the recorded injury with a newly shaped dorsal fin that had healed to 87% of the original size,” the study reports.
“Photographs provided by divers allowed for accurate measurements of fin growth, confirming an approximate 10.7% increase in fin area, indicative of tissue regeneration,” according to the study. “Wound healing rate was calculated to conclude that the initial wound reached complete closure by day 42.”
It counts as the “first example of fin regeneration in a silky shark.”
There is evidence whale sharks have similar healing abilities, the study reports. Anecdotal evidence has also been found in other shark species, including white sharks tagged in the Northwest Atlantic, McClatchy News reports.
The silky shark at the center of the new study was part of an ongoing tagging study funded by the University of Miami Shark Research and Conservation Program, the report states.
University of Miami PhD candidate Chelsea Black led the research, which began when underwater photographer Josh Schellenberg managed — by coincidence — to get
before-and-after shots of the same injured shark.
“In the summer of
2022, 10 silky sharks were tagged with satellite tags for a separate study. Shortly after, a silky shark was spotted with its dorsal fin cut up — in the exact shape of where a satellite tag would be,” Black wrote in a Dec. 14 Instagram post.
“We never expected to see the shark again. Fast forward to summer 2023 and sure enough this silky shark returned to Jupiter. He was spotted by (two photographers) who were able to capture multiple images for me of this newly healed dorsal fin.”
Schellenberg and photographer John Moore both contributed their images to aid in the research, she said.
The identity of the silky shark was confirmed with the help of a National Oceanic and Atmospheric Administration (NOAA) dart tag that was present before and after the fin regenerated, she said.
Silky sharks — named for their smooth-looking skin — are native to the Gulf of Mexico and Florida’s Atlantic coast and can reach up to 10 feet in length, the Florida Museum of Natural History reports.
Their size makes silky sharks a potential threat to humans, but their “oceanic habits make contact with humans a relative rarity,” the museum says. They prefer “the edges of continental shelves and over deepwater reefs,” the museum notes.
“This newfound insight into tissue regeneration and wound healing underscores the importance of further research to understand how they respond to traumatic injury in the face of mounting environmental challenges,” Black wrote.
“Additionally, this study exemplifies the power of collaboration between researchers and the public, including photographers and divers, to expand the scope of research studies and bridge the gap between science and society.”