"Mahi-Mahi is a beautiful fish with a rainbow of dazzling iridescent colors which fade after dying. The back is electric green and blue with gold or silver sides and bellies. The sides have a speckling of spots.
They are among the fastest swimmers in the sea, and their Spanish name is Dorado maverikos which means “golden maverick”. The average commercial size is about 5 lbs, but mahi-mahi can reach up to 50 lbs."
Source: Chef’s Resource
Dolphinfish (aka Mahi Mahi) caught in the U.S. Atlantic with handlines and hand-operated pole-and-lines or trolling lines is a "Best Choice." The population is likely stable, and overfishing is a low concern. However, these fisheries also catch yellowfin tuna, which are depleted in the Atlantic. Management is rated moderately effective, and some conservation measures are in place for dolphinfish.
Mahimahi has a sweet, mildly pronounced flavor similar to swordfish. The lean meat is fairly firm in texture, though not steak-like, and it has large, moist flakes.Darker portions of meat can be trimmed away for milder flavor. The raw flesh is pinkish to grayish-white, though dark along the lateral line. Cooked, the meat becomes off-white.
Mahi performs well on the grill. Though it is not an oily fish, the meat remains nicely moist and can hold up even to blackening. Mahi has a thick skin that should be removed before cooking.