How does the rainbow trout protect its self?

Salmon have evolved to live in large groups, and this is their primary defence against predators.

Like most fish, when a shoal of salmon feel threatened they will begin to 'school' meaning: move together as a group. Groups of animals who look the same and closely mirror each other's movements make it very difficult for a predator to identify a single target.

Biologists call this phenomena a 'shell game' in reference to the con-trick of hiding a pea under one of three shells, shuffling the shells and having the mark try to guess which shell the pea is under. Herding animals, such as antelope or Zebra, have evolved the same technique.

How animals achieve this effect is still the subject of study, though a comparison is often made with a 'Mexican Wave' where a large crowd coordinate their actions by copying their nearest neighbour.

Salmon have evolved to live in large groups, and this is their primary defence against predators.

Like most fish, when a shoal of salmon feel threatened they will begin to 'school' meaning: move together as a group.

Groups of animals who look the same and closely mirror each other's movements make it very difficult for a predator to identify a single target(casually known as a shell game).

How animals achieve this effect is still the subject of study, though a comparison is often made with a 'Mexican Wave' where a large crowd coordinate their actions by copying their nearest neighbor.