A post-mortem of a 13-foot (4-meter) Greenland shark washed up in Newlyn Harbor in Cornwall found that it died of the brain disease called meningitis. Daily Star reported that the creature is already 100 years old but is still considered a juvenile for their species.
Scientists believe it is the first evidence of the disease on the rare shark species that could live up to 400 years old and are known as the oldest living vertebrates on Earth. But they believe that it is still too early to link its death to man-made stressors, such as pollution, to the marine environment.
A dead shark is laying on the beach of Hann before being filleted for sale, in Dakar, on July 22, 2019.
First Meningitis Death Among Greenland Sharks
On March 13, a dog walker first noticed the female shark on a beach near Penzance before it was washed back into the sea and properly examined. But it was later found on the Cornish beach by a tourist boat after two days, MailOnline reported. A necropsy was then conducted on the Greenland shark, an autopsy that is believed to be the first of its kind undertaken on the species in the UK.
Scientists hypothesize that the brain infection may have caused the sudden appearance of the shark from her natural deep-water habitat and why it was stranded and eventually died.
Zoological Society London's (ZSL's) Cetacean Stranding Investigate Program (CSIP) pathologists who conducted the post-mortem determined that it had died from meningitis-like brain disease, marking the first time in the otherwise invincible species.
Furthermore, they said that the shark's brain was slightly discolored and congested from a cloudy fluid that contained a type of Pasteurella bacteria, which likely caused its meningitis.
Veterinary pathologist James Barnett of the Cornwall Marine Pathology Team noted that the shark's body was in dire condition and there were signs of hemorrhage within the soft tissue of its pectoral fin, coupled with slits found in her stomach that suggest it was still alive while being stranded.
CSIP project lead Rob Deaville commented that it is unfortunate that it was only because of an unusual stranding that scientists got an insight into the life and death of Greenland sharks, a species that they know little about. It is not known how it got the infection and the significance of its death in terms of environmental stressors is also unknown.
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Bacterial Infection in Marine Animals
According to MSD Veterinary Manual, marine animals are probably susceptible to the entire range of pathogens. These Gram-negative bacteria include Pasteurella multocida, which causes several outbreaks of hemorrhagic enteritis, depression, and abdominal distress, leading to death in dolphins.
Other bacteria also include Mannheimia haemolytica, which causes hemorrhagic tracheitis among dolphins, Plesiomonas shigelloides which causes gastroenteritis in harbor seals, Burkholderia pseudomallei, which causes fatal outbreaks of diseases among marine mammals, and the Salmonella spp which causes fatal gastroenteritis in manatees and beluga whales.
But the most common types of diseases caused by pathogens among marine animals are actinomycetes, brucellosis, clostridial myositis, pneumonia, erysipelas (Diamond Skin Disease), leptospirosis, streptothricosis (Dolphin Pseudopox, Cutaneous Dermatophilosis), mycobacteriosis, and mycoplasmosis.
RELATED ARTICLE: Odd Stranding Case of Rare 100-Year-Old Greenland Shark in UK Coast Baffled Experts
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