a.k.a.: Common or Atlantic mackerel, Spanish mackerel, tinker mackerel, Pacific mackerel, king mackerel, kingfish

Waters:Most species are harvested off the Atlantic coasts of Europe and North America; there is a Pacific variety as well.

Description (in water): There are many species of mackerel; most are iridescent bluish-green in color with dark horizontal stripes. Common (a.k.a. Atlantic) and tinker mackerel weigh 1 to 2 lbs. on average, while Spanish and king mackerel tend to be somewhat larger.

Description (in market): The firm, dark flesh of the mackerel is fatty and rich with a strong, sweet flavor. The high fat content of the meat should not deter you--most of this is "good" fat rich in Omega-3 oils; only a trace amount is of the cholesterol variety. Mackerel is a scaleless fish; the skin is edible.

Sold as: Whole, steaks, fillets; smoked, salted

Best cooking: It's a good idea to complement the rich, fatty meat with acidic ingredients like citrus- or tomato-based sauces or marinades. You can do almost anything with mackerel--the firm flesh broils, grills, bakes, poaches, and sautés nicely. It can also be minced and used as the base ingredient for Thai-style fish cakes.

When using salted mackerel, soak it overnight in cool water to reduce the saltiness.

Buying tips: An oily fish, mackerel does not freeze well; it's best purchased fresh from the sea. Look for bright, iridescent skin (the fish tends to lose its shimmer soon after the catch--the extent to which the skin has faded should give you a sign of how long the fish has been sitting in the market). It should smell fresh and of the sea.

Substitutes: Bluefish, butterfish, mahi-mahi, pompano, striped bass, tuna

Notes: Mackerel is not a bony fish; you can fillet it yourself, without the help of a fishmonger, if you wish.