Fish show different behavior patterns—some live in groups, while others live and hunt alone.

■ Fish that form large schools

Near the surface and in mid-water, there are few places to hide.
Many pelagic and migratory fish form large schools to reduce the risk of predation.
In a school, each fish is harder for a predator to single out—this is sometimes called the “safety in numbers” effect.

Small fish gather for protection

■ Fish that form small schools

Around the spawning season, several males and females may gather and form a small group.
After spawning, many of these fish return to solitary behavior.

Spawning

■ Fish that live alone

Many fish that live around reefs, rocks, and other structures are territorial and often live alone.
They may use a specific hole or shelter as a home and defend it from intruders with threat displays—or by biting if necessary.

My territory