Sharks who spend too much time in the sun get a tan, researchers have discovered.
However, they do not appear to suffer from skin disease, raising hopes that shark skin could hold the key to beating skin cancer.
‘As far as I’m aware, sharks appear very robust to skin damage and disease,’ said Michael Sweet, a researcher in the School of Biology at Newcastle University’s Newcastle Institute for Research on Sustainability.
‘I don’t know what makes shark skin so special, but it definitely needs to be studied.
‘There have been a lot of attempts to induce melanomas in sharks to no affect.’
Researchers hope that if they can find the secret of how shark skin protects itself, it could be used to create a ‘shark lotion’ to protect human skin.
Another recent study, undertaken by the California State University Shark Lab, also looked at tanning in sharks.
Hammerhead shark pups held in a shallow clear seawater pond at the Hawaii Institute of Marine Biology darkened after several weeks, where UV levels are 600 times greater than those in their regular habitat of Kaneohe Bay.
An opaque filter was placed over the pectoral fins of untanned sharks to cut out UV light, to determine whether the darkening was due to solar radiation.
‘Areas of skin from under the opaque filter were untanned, whereas all other skin exposed to direct sunlight was considerably darker, resulting in distinct ‘tan lines’, the researchers said.
Our experiments demonstrated that the sharks were truly sun-tanning and that the response was, in fact, induced by the increase in solar radiation, particularly UV.
‘These sharks increased the melanin content in their skin by 14 percent over 21 days, and up to 28 percent over 215 days.’
The researchers said the only other animals known to suntan are mammals.
Attribution: Medical Daily, Mail Online