Have you ever seen a tornado? The violent, swirling winds of tornadoes understandably strike fear into the hearts of even the bravest souls. Only the most daring storm chasers want to get close to a tornado…and they put themselves in danger purely for the pursuit of science.

But what if you encountered a tornado underwater? And what if it was made of swirling fish instead of cyclonic winds? That amazing sight would be what some scientists call a fishtornado" and it's a real phenomenon!

Photographer and marine scientist Octavio Aburto caught this unique phenomenon in pictures and video during his studies at Cabo Pulmo National Park. This large marine reserve in Mexico's Sea of Cortez sits north of Cabo San Lucas off the tip of Baja California.

At Cabo Pulmo National Park, Aburto studies the movements and courtship behavior of the bigeye trevally, which is sometimes known as the bigeye jack, great trevally, six-banded trevally, and dusky jack. It's a particular species of a common large fish that's part of the jack family Carangidae.

During his studies, Aburto witnessed the unique courtship behavior of the bigeye trevally, in which humongous groups of the fish swim rapidly together and around one another at high speeds. Their behavior creates a moving, swirling column of fish that can only be accurately described as a fishtornado." A fishtornado" can be made up of thousands of fish!

Aburto witnessed these fish tornadoes on many occasions, but it took him nearly three years to be in the right place at the right time to capture the phenomenon in pictures and video. His incredible photographs and videos have become sensations on the Internet.

Marine biologists who have seen the photographs and videos point out that such courtship behavior amongst fish is not uncommon. It doesn't always rise to the level of a fishtornado," however, so what Aburto was able to capture is still special.

If you know much about fish, you probably know that it's not uncommon for fish to swim in groups. Upon seeing a group of fish swimming together, many children will immediately exclaim, “A school of fish!"

School is actually a technical term with a particular meaning when it comes to a group of fish. Any group of fish congregating together is called a shoal. For a shoal to be considered a school, it must meet certain criteria.

If you see a simple social grouping of fish, it's a shoal. If, however, those fish swim together in a synchronized manner — swimming together at the same speed, in the same direction, and turning at the same time — then they can be called a school.

Why do fish tend to hang out in groups, whether they're shoals or schools? There are several reasons, but they all boil down to the fact there's safety — and success — to be found in groups.

Fish in groups find food easier. Swimming in groups also helps fish find potential mates. If danger approaches, it's much safer to be part of a large group of fish than to be on your own. And who knows? It may just be more fun for fish to hang out with friends. Don't you think it would be fun to swim as part of a fishtornado"? We do!

Wonder What's Next?

Be sure to tune in tomorrow for a Wonder of the Day that looks like it’s going to be spectacular!