The giant red blob looked and moved like a shark, and would have weighed an estimated 40 tons.

But as researchers from the Atlantic Shark Institute watched in perplexment and fascination, the alarming red blob scattered into thousands of smaller fish.

What researchers were looking at was actually a crowded school of Atlantic mackerel, which just happened to take on the shape of a giant shark.

Atlantic mackerel tend to huddle close together as a hunting technique.

Rather than individually hunt for plankton and other morsels, mackerel crowd together in a tightly packed phalanx.

Evading a single mackerel is difficult enough for a plankton, but ending up a tasty snack is inevitable when you are confronted by a wall of fish mouths.

Scientific evidence points to megalodon having lived between 16 million and 2.6 million years ago, going extinct at the end of the Pliocene Epoch when the world’s oceans were much colder than today’s.

Megalodons are best remembered for being the antagonist in the film The Meg, which is regarded as one of Jason Statham’s most realistic movies.