The super-rare Greenland shark that washed ashore in England last month had a brain infection when it died, according to an animal autopsy of its remains.
Pathologists discovered evidence of meningitis, an inflammation of the protective membranes that cover the brain and spinal cord, according to a statement from the Zoological Society of London (ZSL). This is the first reported disease-related death in a Greenland shark (Somniosus microcephalus), an elusive, long-lived species that lives in the deep waters of the Arctic and North Atlantic.
"During the post-mortem examination, the brain did look slightly discoloured and congested and the fluid around the brain was cloudy, raising the possibility of infection," James Barnett, a pathologist with Cornwall Marine Pathology Team, a part of the U.K. Cetacean Strandings Investigation Programme (CSIP) and ZSL, said in the statement.
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A microscopic examination of the Greenland shark's brain fluid revealed Pasteurella, a species of bacteria. "This may well have been the cause of the meningitis," Barnett said.
The Greenland shark was likely about 100 years old when it died. This may sound old, but it's quite young for a Greenland shark, making this individual a juvenile female. While it's unknown how long these sharks can live, they can make it to at least 272 years of age, a 2016 study published in the journal Science found.
The deceased shark, which measured 13 feet (4 meters) long and weighed 628 pounds (285 kilograms), stranded near Newlyn Harbour in Cornwall, in southwest England, on March 13, but the tide swept the animal's body back out to sea, Live Science previously reported. A recreational boating company recovered the shark's body on March 15, making it the U.K.'s second recorded Greenland shark stranding to date.
The meningitis found during the necropsy, or animal autopsy, likely explains why the shark had ventured out of its natural deep-water habitat and eventually stranded, according to the statement.
The shark's body was damaged, and there were signs of hemorrhaging within the soft tissue around the pectoral fins, which, coupled with the silt found in its stomach, suggested the shark was still alive when it washed ashore, Barnett said. "As far as we're aware, this is one of the first post-mortem examinations here in the U.K. of a Greenland shark and the first account of meningitis in this species," Barnett said.
The shark's death gives "insight into the life and death of a species we know little about," Rob Deaville, CSIP project lead, said in the statement. "Ultimately, like most marine life, deep sea species such as Greenland sharks may also be impacted by human pressures on the ocean, but there is not enough evidence at this stage to make any connections."
The team plans to publish a research study on the shark's postmortem report.
Originally published on Live Science.
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Laura is the archaeology and Life's Little Mysteries editor at Live Science. She also reports on general science, including paleontology. Her work has appeared in The New York Times, Scholastic, Popular Science and Spectrum, a site on autism research. She has won multiple awards from the Society of Professional Journalists and the Washington Newspaper Publishers Association for her reporting at a weekly newspaper near Seattle. Laura holds a bachelor's degree in English literature and psychology from Washington University in St. Louis and a master's degree in science writing from NYU.