By: AgroNature Admin
Commercial fishers uncovered a first-of-its-kind discovery while trawling waters in Sardinia, Italy – a skinless, toothless shark.
The blackmouth catshark was pulled in the depths near Sardinia but appeared to be in good health amid a number of abnormalities.
Experts investigating the specimen say the shark lost its skin after being exposed to chemically contaminated sites, as well as acidification due to climate change.
The skinless catshark was discovered by a team at the University of Cagliari, Italy, which says this is the first of its kind.
Investigations into the animal’s anatomy, published in the journal Fish Biology revealed that the fish possessed none of the structures associated with elasmobranch skin, the group that contains sharks, and is believed to be the only time such a creature has been found free-swimming in the ocean.
“For elasmobranch sharks, skin plays an important role as a chemical and mechanical defense. It secretes mucus that is considered the first line of its immune system, preventing microbes from forming colonies on its surface as it contains antibacterial proteins. Uniquely made up of denticles – overlapping teeth-shaped structures – it’s also a strong mechanical barrier against certain predators and ectoparasites,” it says.
The team said the shark was caught by trawl in July 2019 at a depth of 500 meters (1,640 feet) in Sardinian waters as reported by IFL science
Given the significance of skin to a shark’s survival, the researchers report that the condition would be potentially fatal and yet it was discovered well developed and seemingly in good health.
Reasons for why the shark ended up toothless on the inside and outside range from natural to human-linked explanations.
The authors suggest that long-term exposure to chemically contaminated sites could be blamed as well as ocean warming or acidification due to climate change.
Alternatively, it says this might be an error that occurred naturally during the animal’s embryonic development.
In an ever-changing environment, the researchers urge that understanding such abnormalities is an important step in protecting marine animals as-” if we don’t find out what triggered our skinless shark, we could end up with a lot more skinny dippers in our oceans.”