Mackerels include several species of fish. The common Atlantic mackerel has a deep-blue back, crossed by black stripes, and a light-colored lower body. Two other kinds are the Spanish mackerel and the golden spotted Pacific mackerel. All have oil-rich, tender flesh.
Mackerels are related to tunas. Both are speedy swimmers because the rays of their broadly forked tails overlap their last vertebral bones, giving the tails rigid and powerful propulsion. Each spring, great schools of mackerel appear in shallow coastal waters, having moved in from unknown, deeper ocean areas. In these coastal banks, they lay their eggs and may be caught in early summer, just after spawning.