Atlantic mackerel
The Atlantic mackerel is an active, fast-moving fish that must keep in constant motion to bring in enough oxygen to survive. It swims using short movements of the rear of its body and the caudal fin. Unlike other mackerel, Atlantic mackerel do not leap out of the water unless attempting to escape a predator. They form large schools, consisting of individuals of the same relative size, near the ocean surface during all seasons but winter. Because larger fish have a greater ratio of muscle mass to surface area, schools of larger fish are able to swim more quickly than schools made up of smaller individuals.