The biggest fish in the world are girls

Whale sharks were already known as the biggest fish in the sea. And don’t be intimidated by “shark” — these massive animals are known to be docile.

But researchers have officially handed the crown specifically to female whale sharks.

Scientists followed 54 whale sharks for more than a decade to study the biology of how these little-studied creatures grow.

And they found something interesting: Males grow fast and reach 30 feet long. Females grow much slower, only about 20-30 cm per year, but they reach lengths up to 40-45 feet.

There are advantages for female whale sharks to grow so large, the scientists said.

"Only one pregnant whale shark had ever been found, and she had 300 young inside her," said Mark Meekan, a fish biologist at the Australian Institute of Marine Science and lead author of the new paper.

The new findings will help in conservation efforts because it will help researchers understand whale shark behavior better.

For instance, a whale shark’s slow growth rate means that it faces more dangers, like targeting fishing and collisions with ships, before reaching maturity.

"If you're a very slow-growing animal and it takes you 30 years or more to get to maturity, the chances of disaster striking before you get a chance to breed is probably quite high," Meekan said.