Researchers in Australia discovered a tumor on the mouth of a great white shark, debunking the misconception that sharks cannot get cancer. The tumor is one foot long and wide.
Researchers also discovered another tumor on the head of a bronze whaler shark, Live Science reported. The findings were published in the November issue of the Journal of Fish Diseases.
"This is a very unusual sight as we have never before seen a [great] white shark with tumors," Fox Shark Research Foundation biologist Rachel Robins, who was involved in the study, told Live Science.
For over a century, scientists have known that sharks can develop cancer. But long-held cultural beliefs that the animals couldn't get cancer was encourage by people who sell shark cartilage under the pretense that it cures cancer, University of Miami shark researcher David Shiffman told Live Science. However, there is no scientific evidence proving shark cartilage is a cancer cure.
"Sharks get cancer," Shiffman told Live Science. "Even if they didn't get cancer, eating shark products won't cure cancer any more than me eating Michael Jordan would make me better at basketball."
But the demand for sharks and their parts persists. According to a study published earlier this year, almost 100 million sharks are killed every year, Live Science reported. Those deaths are not all attributed to gathering cartilage, though. Sharks are also captured for their oil, and for their fins to make shark fin soup.
According to Live Science, experts do know that the rate of aquatic animals with cancer has increased over the last 20 years. The direct cause for the cancer is unknown, but there is a concern belief that human's actions contribute to the increase, the study said.
"The main take-home message from the study is that it adds to the growing evidence of tumor formation in sharks, contrary to popular belief that sharks do not suffer from such anomalies," Robbins told Live Science.
