What is a Group of Fish Called?

While people use both words casually, in marine biology, there is a very strict difference between the two:

1. A Shoal of Fish: This is any random, massive group of fish hanging out together in the same area for social reasons. They might be swimming in different directions, looking for food independently, and just relaxing.
2. A School of Fish: This is highly organized. When a shoal suddenly feels threatened by a shark, they instantly snap into a military formation. They swim tightly packed together, moving in the exact same direction at the exact same speed, turning simultaneously like a single massive organism. This coordinated behavior is called 'Schooling'.

Swimming in a highly organized school is a brilliant survival tactic. When millions of tiny silver fish swim tightly together and turn sharply, the flashing silver scales visually confuse large predators. The shark's brain gets overwhelmed by the visual chaos, making it nearly impossible to lock onto one single fish to eat.

Not all ocean animals use the word 'school':

• A group of Whales or Dolphins is called a Pod.
• A group of Jellyfish is called a Smack or a Bloom.
• A group of Sharks is called a Shiver.