Shark May Have Eaten A Pregnant Shark
“A pregnant porbeagle shark may have been eaten by a great white shark near Bermuda, in the first recorded incident of its kind,” according to a story in the New Scientist.
The report said, “In October 2020, Brooke Anderson, then at Arizona State University, and her colleagues tagged a pregnant porbeagle shark [Lamna nasus] south-east of Cape Cod in Massachusetts as part of research into pregnant shark migration.
“The researchers used pop-off tags, which continuously measure the depth and temperature of the shark. When the tag detaches from the shark and floats to the surface, the stored data is pinged back to shore.
The pregnant porbeagle shark after being tagged by researchers. Photo courtesy of Jon Dodd.
“Five months after the pregnant shark was tagged, the tag resurfaced south-west of Bermuda and the researchers received data on its recent movements.
“The shark had spent five months cruising through waters at a depth of 600 to 800 metres during the day and 100 to 200 metres at night, with water temperatures varying from 6.4 to 23.5°C [43.5 to 74.3°F], according to the tracker.
“But from 24 March 2021, something changed. The ambient temperature around the pregnant shark remained between 16.4°C and 24.7°C [61.5°F and 76.5°F], despite it swimming at a similar depth to before. As well as the change in temperature, there was a shift in diving patterns.
“It suggests the tag – and the attached shark – was eaten, says Anderson, who now works at North Carolina Division of Marine Fisheries. “All our evidence points to the same conclusion,” she says. “It’s clear that our porbeagle shark was eaten by another shark.”
“A great white shark [Carcharodon carcharias] is the most likely culprit, the team concluded, as it is the only predator in the area large enough to mount such an attack. The diving patterns and body temperature of a great white also match the data collected by the tag.”
“This was a big female shark that got eaten,” says team member James Sulikowski at Oregon State University. “So something probably larger than it had to have attacked it.”
You can read the full story here on New Scientist.
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Category: All, Environment
