An "infamously" blood-thirsty pair of orcas who devoured a total of 17 sharks in a single day have baffled marine biologists with their insatiable appetite.
The duo - who have been on the radar of scientists since 2015 - slaughtered 17 sharks off the coast of South Africa late last month, gorging themselves on the animals and leaving their carcasses to float ashore at Pearly Beach, a village located along the southernmost tip of the country.
Marine biologist Dr Alison Kock said the orcas had only eaten livers of the broadnose sevengill sharks, a strange practice she'd observed in the pair for eight years.
READ MORE: Bindi Irwin shares health battle
READ MORE: The shelving 'trick' supermarkets don't want you to know
"At least 17 sevengill sharks have been killed by infamous killer whale pair Port and Starboard this week in South Africa," Kock said on Twitter.
"Only the livers were eaten with the leftover carcasses washing ashore.
"We first observed this pair hunting sevengill sharks in False Bay, Cape Town in 2015 ... the drama didn't stop there.
"In 2017, this pair then started targeting great white sharks, ultimately resulting in the sharks abandoning established aggregation sites."
https://twitter.com/UrbanEdgeSharks/status/1629136252153864192Kock explained orcas learn from experimenting with prey and can "remember" specific types of foods that they can then continue to hunt.
"They likely initially learn by experience when first predating a new species," she said.
READ MORE: Bodies of abducted pair found in medical clinic
This means that once the orcas are aware of the liver's location on a shark, "they will remember it forever and become more efficient".
Shark livers are highly nutritious and contain large levels of fats and vitamins.
"Orcas may have learned that consuming shark livers provides high energy and nutrients," Kock told Live Science.
"Sharks' livers are large and buoyant, and they float to the surface of the water when a shark is killed.
"This makes them easy for orcas to spot and access, compared to other organs that may sink to the bottom or be harder to locate."
Sign up here to receive our daily newsletters and breaking news alerts, sent straight to your inbox.
