A silvery torpedo glides beneath the waves. It flashes electric blue, glittering gold and brilliant emerald, then thrusts several feet into the air before plunging back to the depths. That torpedo is a fish, Coryphaena hippurus, known in Spanish as “dorado” and more commonly as mahi-mahi. The mahi-mahi’s aerial acrobatics undoubtedly gave rise to another common nickname, “dolphinfish,” but there is no familial relationship to the mammal dolphin.
The color changes of this “golden” fish are the product of pigment-containing, light-reflecting cells called chromatophores that are found in many lower vertebrates. Triggered by external stimuli and hormone and neural interactions, the ability to rapidly flicker colors and patterns serves many functions, from communication and camouflage to warning of danger. It not only enables survival, but also signifies distress, injury or death, as a dying mahi-mahi fades to a faint greyish-yellow hue.
Living in deep waters of tropical and subtropical regions throughout the Atlantic, Pacific and Indian Oceans, adult mahi-mahi can grow to nearly 7 feet in length and weigh almost 90 pounds. They have a voracious appetite, consuming up to 20 percent of their body weight daily. Mahi-mahi can swim nearly 40 miles per hour and put up a powerful fight that makes this agile predator one of the most popular game fish for offshore anglers.
In the Kitchen:
Mahi-mahi is a thick, firm fish with a hearty, almost meaty texture and a mild to moderate flavor. Some people consider the bloodline to be visually unappealing and strongly flavored, so it often is trimmed away. If present, the skin can help fillets stay together during cooking, especially when grilling or sautéing. When cooked, mahi-mahi is opaque and flakes easily with a fork into large, tender pieces. The recommended minimum internal temperature is 145 degrees Fahrenheit.
A relatively lean fish, mahi-mahi is best suited to quicker cooking preparations such as sautéing, broiling, baking on a sheet tray at high heat or grilling. Blacken or tempura-fry it for tacos, or pan-sear fillets with onions, mushrooms and a garlicky lemon butter herb sauce. Oven-roast mahi-mahi en papillote (in parchment paper) with asparagus, cherry tomatoes and basil during the spring or summer, and with pear, sweet potato, leek and thyme in autumn or winter. To honor its warm-water origins, use bold ingredients from those regions: coconut milk or flakes, mango, lime and pineapple, sweet or hot peppers, ginger, lemongrass and kaffir lime leaves, or a cilantro or mint chutney.
Substitutes for mahi-mahi include halibut, grouper, flounder, snapper and amberjack. Though fishmongers typically remove the tiny pin bones in fish prior to sale, always err on the side of caution; run your hand over the fish to check for bones and use tweezers for easy removal.
In the Clinic:
Mahi-mahi is a lean fish high in protein. One 3-ounce cooked fillet has 93 calories and approximately 20 grams of protein. With less than 1 gram of total fat, each fillet contains 0.022 grams and 0.096 grams of eicosapentaenoic acid and docosahexaenoic acid, respectively.
A 3-ounce portion contains about 72 percent of the Daily Value for the antioxidant selenium, 80 milligrams of cholesterol and 96 milligrams of sodium. It also is an excellent source of vitamins B12, B6 and B3 (niacin), and provides smaller amounts of potassium and magnesium.
The U.S. Food and Drug Administration and Environmental Protection Agency consider mahi-mahi a “good choice” based on mercury levels but recommend limiting consumption to one serving per week for young children, pregnant and breastfeeding women and those who might become pregnant. A serving is 4 ounces for adults; a child’s serving depends on age.
Thanks to their warm habitats, mahi-mahi spawn intermittently year-round but have two “peak” seasons: from March to May and from September to November.
According to the National Oceanic and Atmospheric Administration Fisheries, wild-caught mahi-mahi from the United States is a sustainable source of seafood. Because of their rapid growth and maturation, high productivity and relatively short life cycle, mahi-mahi can withstand heavy recreational and commercial fishing pressures.
When selecting fresh fillets, look for firm, light pink flesh with a mild aroma. There should be no fishy or ammonia-like smell. The bloodline, if present, is safe to eat and should be bright red, never brown or black. Preferred market weight of mahi-mahi is 15 pounds or more, and therefore it is rarely sold whole. Best prepared and eaten the day of purchase, fresh fish can be refrigerated up to two days on a plate or tray covered loosely with a paper towel or plastic wrap.
Mahi-mahi is commonly sold frozen in bags of 4- or 6-ounce vacuum-packed skinless fillets. Good-quality frozen fish should be rock-hard, appearing somewhat shiny with no evidence of freezer burn or defrosting, such as excess ice crystallization inside the package or fillets in contorted shapes. Well-wrapped frozen fillets can be stored in the freezer for up to eight months. Thaw in the refrigerator overnight, removed from packaging and covered loosely; to thaw fillets quickly, place in a sealed plastic bag and immerse in cold, potable water just before cooking.
For foodservice use, mahi-mahi is available in multi-pack cases with individually frozen and vacuum-packed skinless fillets ranging from 4 ounces to 10 ounces. Other frozen options include similarly sized skin-on fillets, larger portions to be cut onsite or high-end specialty cuts such as cheeks (small portions of mild, sweet and tender flesh from between the eye socket and gills).
Advice About Eating Fish For Women Who Are or Might Become Pregnant, Breastfeeding Mothers, and Young Children. United States Environmental Protection Agency and U.S. Food & Drug Administration website. Accessed January 8, 2020.
Burgman J. Greatest Gamefish. Outdoor Life website. Published April 7, 2011. Accessed January 8, 2020.
Dolphinfish. Monterey Bay Aquarium Foundation website. Accessed January 8, 2020.
Dolphinfish Recommendations. Monterey Bay Aquarium Foundation website. Accessed January 8, 2020.
Mahi-Mahi. Harbor Seafood website. Accessed January 8, 2020.
Mahi-Mahi Flavor Profile. Chef’s Resources website. Accessed January 8, 2020.
Nutrition Facts Label and Allowable Nutrient Claims for a single 4 oz. Hawaii Seafood Council and NOAA website. Accessed January 8, 2020.