King Mackerel
Color of back iridescent bluish green; sides silvery, streamlined body with tapered head; no black pigment on front of dorsal fin; lateral line starts high and drops sharply below the second dorsal fin; young fish often have yellow spots like those of the Spanish mackerel.

Spanish Mackerel
Color of back green, shading to silver on sides, golden yellow irregular spots above and below lateral line; front of dorsal fin black; lateral line curves gently to base of tail.

Other Mackerels around the world

• Atlantic Spanish mackerel - Scomberomorus maculatus
• Blue mackerel - Scomber australasicus
• Broadbarred king mackerel - Scomberomorus semifasciatus
• Chub mackerel - Scomber japonicus
• Australian spotted mackerel - Scomberomorus munroi
• Double-lined mackerel - Grammatorcynus bilineatus
• Indian mackerel - Rastrelliger kanagurta
• Indo-Pacific king mackerel - Scomberomorus guttatus
• Island mackerel - Rastrelliger faughni
• Japanese Spanish mackerel - Scomberomorus niphonius
• Streaked Spanish mackerel - Scomberomorus lineolatus
• Spotted Spanish mackerel - Scomberomorus guttus

Season
The mackerel follows the herring season, starting in October and continuing until March.

Medicinal properties
Mackerel is a rich, oily fish, and as such is an excellent source of omega-3 fatty acids, which have been shown to reduce the risk of heart disease and other serious illnesses.

Nutritional Values
Fat content: 28% to 30% in October, decreasing steadily to 20% to 24% in March.
Atlantic mackerel is extremely high in vitamin B12.

Market

• Fresh Mackerel
• Cold smoked
• Hot smoked
• Peppered

Buying
Because of its high oil content, fresh mackerel is very perishable, so shop for it with particular care. This fish is marketed dressed or in fillets.

Spanish and jack mackerel have relatively light, mild-flavored meat, while Atlantic, Pacific (also called Blue), and king mackerel have more of the richer-tasting dark flesh and a more pronounced flavor.

Storing
The most important thing about storing mackerel is to do it briefly--it's best to eat the fish the same day you buy it, or no more than 24 hours after purchase. Keep the fish well inside the refrigerator--away from the door, where the temperature fluctuates each time the door is opened.

Culinary Uses
Atlantic mackerel are sought after for food either cooked or as sashimi. It consists mostly of red meat.

Mackerel can be poached, baked, sauteed, or broiled. A citrus or vinegar marinade, or a tart or mustard-based sauce, helps temper its richness.

Poaching: Both whole and fillet mackerel can be poached. In a large skillet, heat water and lemon slices or a combination of wine and water to a gentle simmer. Add mackerel, cover and simmer until just done, about 15 minutes for whole mackerel, five to seven minutes for fillets. Serve with lemon wedges or a tart sauce.

Baking: Whole mackerel or fillets can be baked. Place mackerel in a non-aluminum pan and top with a mixture of sauteed garlic, tomatoes, chopped olives, and roasted peppers. Bake at 400°F until flesh can be just be pierced with a knife, but is not falling apart, about 15 minutes for whole fish and seven minutes for fillets. Mackerel intended for baking can also be marinated or rubbed with a dry rub; see "Broiling or Grilling" below.

Sauteeing: Mackerel fillets can be sauteed in a very short time. Because mackerel is an oily fish, if you choose to saute it, try doing so in a skillet without any added fat, or only a slight brushing of oil. Preheat the pan over medium heat, add the mackerel skin-side down and saute three minutes or until it begins to release its oil. Cover and cook just a few more minutes until done. Serve with a lemon wedge.