No. Fish can not knock themselves out, but they can get stressed out from hitting their head on their tank.
Depends on how big the fish is.
knock it into the tank
it shoots a water jet are bug to knock them into water to eat them
they dont
Move on.... plenty of fish as they say.
to protect themselves
their mouths
they can't.
fleeing.
they swim away
they protect themselves from larger carnivorous fish by hiding among the tentacles of Sea Anemones- which would sting and eat the larger fish... The Clown fish is immune to the Sea Anemone's stings.
Bass feed on insectlarvae ,crustaceans, and fish smaller than themselves.