Researchers have a new idea about why fish swim in schools.

Transcript

A MARTÍNEZ, HOST:

Researchers have a new idea about why fish swim in schools. Turns out when fish swim together in turbulent water, they use nearly 80% less energy.

LEILA FADEL, HOST:

Yangfan Zhang studies animal biology at Harvard. He led the study published in the journal PLOS Biology. He's also a cyclist.

YANGFAN ZHANG: So it's a little bit like when the cyclists are doing the bicycle race, they tend to group together in the peloton. And we find this same phenomenon in the fish.

MARTÍNEZ: Yeah, it's called drafting, and it's used for car racing, too. The fish or cyclists or cars in the front have to work the hardest to get through the air or water resistance. The others following the leaders wait to save energy, then they take turns leading the pack.

FADEL: So what else could be behind fish swimming together? Zhang says there are a lot of reasons.

ZHANG: There are mating behavior. There are safety in numbers. There's also migrations. So they do it to achieve their lifetime fitness, so they can grow better. They can reproduce. They can sustain the species.

FADEL: Zhang and his co-author studied a fish called the giant danio. These fish are strong swimmers. They tend to stick together, and they like to swim against the current.

MARTÍNEZ: By studying these fish in a lab, the researchers could compare solo swimmers to those in groups. The ones in the groups benefited from using less energy. It's an effect known as turbulence sheltering.

ZHANG: If they can go from A to B more efficient in terms of their energy, that means they have a higher chance to make their destination. Also if they use less energy, they can have energy for other key activity - maybe to look for food, for mating or just to explore.

FADEL: Zhang says it can be hard to measure how much energy animals use. But it's important because it helps us understand how fish spend their time.

MARTÍNEZ: Plus, there's a lot to learn from schools of fish. Imagine a school of drones, a drone light display, maybe - flying them in a certain formation might help them use less energy.

FADEL: For Zhang, there's also the wonder of learning about human society through nature.

ZHANG: For scientists, we always find inspiration from nature by observe how plants, how animals, how the nature works. And they teach us so much.

MARTÍNEZ: So there you go. The old saying still holds up. Teamwork makes the dream work.

FADEL: Are you talking to me, A?

MARTÍNEZ: Absolutely.

MARTÍNEZ: Absolutely. Transcript provided by NPR, Copyright NPR.