One summer day off the northern coast of New Zealand, Rochelle Constantine noticed something strange on the water’s surface.

Somehow, a large orange octopus has been riding a mako shark off the coast of New Zealand. Researchers are mystified.

But in fact, any big shell will do—such as a conch. With a few of its suckers, this octopus is holding two halves of a clamshell. As you watch, it drops them and hoists itself up a little.

A shortfin mako shark, the fastest-swimming shark in the world, was caught on camera with an octopus catching a ride on its back off the coast of New Zealand.

The Dumbo octopus is an elusive cephalopod that gets its name from its large ear-like fins, which resemble those of the lovable Disney elephant. But there's still lots we don't know about these ...

So much so that they may be Earth's next big species if ours ends up going the way of the dinosaurs. While an octopus-dominated future may seem "improbable" at the moment, it "wouldn’t be the ...