Orca whales have claimed the life of another great white shark by eating its liver and leaving it for dead, making it the fourth such gristly death in less than two months.
During a four-day period in early May, researchers reported finding the bodies of three great white sharks (Carcharodon carcharias) that had washed ashore along South Africa’s Western Cape province. All of these sharks were mysteriously missing their livers, necropsies (animal autopsies) showed.
Now, a fourth dead, liverless shark has washed ashore, according to a post today (June 26) on the Marine Dynamics blog, a site hosted by a shark cage diving company. The newly discovered 13-foot-long (4 meters) male shark was missing its liver, testes and stomach, according to the blog post. [See Photos of the Shark Necropsies]
No one saw the sharks’ last moments, but their injuries indicate that orcas, also known as killer whales (Orcinus orca), were the culprits, the researchers said.
“This is the fourth documented deceased white shark since May that we can connect to Orca predation” Alison Towner, a white-shark biologist for the Dyer Island Conservation Trust in South Africa, wrote on the Marine Dynamics blog. “We don’t really know how long the sharks will stay away from the area as a result of predation pressure.”
Although orcas aren’t known to regularly hunt great white sharks, “it’s not unprecedented,” said Andrew Nosal, an assistant professor of biological sciences at Saint Katherine College in San Marcos, California, and a visiting assistant researcher at Scripps Institution of Oceanography in San Diego. (Nosal was not involved in the recent shark analyses.)
Scientists know that both orcas and great whites live off the western coast of South Africa, where the Atlantic and Indian oceans meet. Although Nosal wasn’t aware of orca-on-shark attacks in that area, he had heard of instances in which orcas have hunted the sharks in…