Marine Mystery: The Porbeagle Predation Puzzle

Who killed the pregnant porbeagle?

In a marine science version of the game Cluedo, researchers from the US have now accused a larger shark, with its deciduous triangular teeth, in the open sea southwest of Bermuda. This scientific whodunnit is published in Frontiers in Marine Science.

Life Cycle and Conservation Concerns

Porbeagles are sharks from the Atlantic and South Pacific Ocean and the Mediterranean. They are large, active, powerfully built – up to 3.7 meters (12.1 feet) long and weighing up to 230 kg (500 pounds) – and long-lived, living up to 30 or even 65 years. Females don’t reproduce until they are about 13 years old, and then give birth to an average of four pups every one or two years, born live after a gestation period between eight and nine months.

Because of their slow reproductive cycle, porbeagle populations cannot recover quickly from persecution, recreational fishing, bycatch, and habitat loss and degradation to which they currently are exposed. Indeed, Northwest Atlantic porbeagles are listed as endangered on the IUCN Red List of Threatened Species, while the Northeast Atlantic and Mediterranean populations are critically endangered.