Mahi-Mahi (Coryphaena hippurus) is a highly sought-after fish worldwide, prized by anglers and seafood enthusiasts. This powerful, fast-swimming predator, also called Dolphinfish or Dorado, is instantly recognizable for its brilliant coloration. Despite often being served as a skinless fillet, which leads to confusion, this ray-finned fish does have scales. The nature of these scales and the fish’s other unique physical traits are components of its anatomy.
The Specifics of Mahi-Mahi Scales
Mahi-Mahi are covered in cycloid scales. These scales are small, thin, and overlap like shingles, featuring a smooth outer edge that contributes to a streamlined body contour.
This arrangement helps reduce drag and fluid friction as the fish moves at high speeds through the water. The inconspicuous nature of the scales means they are easily missed during processing, leading many to believe the fish is scaleless.
Because the scales are thin and tightly affixed to the skin, they are typically removed along with the skin during filleting. This is common practice for the species and confirms the Mahi-Mahi’s classification as a true bony fish.
Distinctive Non-Scale Physical Characteristics
Beyond its scales, the Mahi-Mahi possesses several striking anatomical features. Its body is compressed and elongated, tapering toward a deeply forked tail, an adaptation for its rapid, pelagic lifestyle.
A notable trait is the pronounced sexual dimorphism in the head shape of mature fish. Male Mahi-Mahi, called “bulls,” develop a steep, almost vertical bony forehead, giving the head a blunt, squared-off appearance. Females, or “cows,” retain a smoother, more rounded head profile.
The fish’s dramatic, iridescent coloration is captivating when alive, displaying dazzling blues and metallic greens on the back and golden-yellow on the flanks. This brilliant color shifts and fades rapidly upon death, typically dulling to a muted yellow-grey. The dorsal fin runs continuously along nearly the entire length of its back.
Clarifying the Common Names and Misunderstandings
The common nomenclature surrounding Coryphaena hippurus has caused confusion, primarily due to the name “Dolphinfish.” This name has no biological connection to the marine mammal. The fish likely received this moniker because its habit of swimming and leaping near the surface reminded early sailors of the mammal.
To eliminate this misclassification, the Hawaiian name “Mahi-Mahi” has become the preferred term in the global seafood market. “Mahi-Mahi” translates to “strong-strong,” referencing the fish’s power and speed.
The Spanish name, “Dorado,” is also frequently used, particularly in the Pacific and the Caribbean. Meaning “golden,” this name references the fish’s stunning yellow and gold hues when freshly caught. Utilizing these specific names clarifies that the popular food fish is a separate species from the mammalian dolphin.