The External Appearance of a Whole Escolar
At a glance, a whole escolar might be mistaken for other deep-water species, but several key features set it apart. The most noticeable characteristic is its coloration, which ranges from a dark brown in younger fish to a deep, jet-black in older, more mature specimens. It possesses a streamlined, elongated body shape, technically known as fusiform, which is built for speed in its deep-ocean habitat. This sleek profile has earned it the common name 'snake mackerel'.
Examining the head, the escolar features a distinctively jutting lower jaw and large eyes, which are an adaptation for hunting in the low-light conditions of deep tropical and temperate waters. Looking towards the tail, you can clearly see a prominent lateral keel on the side of the caudal peduncle, flanked by a smaller keel above and below. It also has a series of four to six small finlets located after both the second dorsal and anal fins.
The Internal Appearance of Escolar Fillets
When prepared as fillets, the visual appearance of escolar changes dramatically and helps explain why it is so often mislabeled. The raw flesh is a brilliant, pearlescent white, sometimes appearing a light cream color. This stark white color is one of the key reasons it is commonly passed off as 'white tuna' in sushi bars.
The most distinctive feature of the flesh, however, is its texture and high oil content. When pressed, the raw fillet should feel firm yet satiny and oily. This buttery texture comes from the high concentration of indigestible wax esters (gempylotoxin) that the fish stores in its tissue, an oil humans cannot fully metabolize. When cooked, the flesh becomes a snow-white color and maintains its firm, fatty consistency, making it a favorite for grilling and broiling.
Escolar vs. Tuna: A Side-by-Side Comparison
Understanding the differences in appearance between escolar and true tuna is critical for identifying potential mislabeling. While both are fast swimmers with streamlined bodies, their physical and internal characteristics are quite distinct.
| Feature | Escolar | Tuna (e.g., Albacore) |
|---|---|---|
| Exterior Color | Dark brown, becoming jet-black with age. | Varies by species, often metallic blue, silver, or yellow. |
| Body Shape | Long, slender, and sleek, resembling a snake mackerel. | More muscular and robust, less snakelike. |
| Flesh Color | Bright, satiny white or light cream. | Albacore has a pinkish hue; other species vary. |
| Flesh Texture | Oily and buttery due to high wax ester content. | Firm and meaty, but without the high wax ester content. |
| Head | Large eyes and a prominent, jutting lower jaw. | Smaller eyes relative to body size, different jaw structure. |
Key Visual Characteristics for Identification
To summarize, here are the most important visual cues for identifying escolar in different forms:
- Whole Fish: Look for the characteristic dark brown or black coloration, the slender, snake-like body, large eyes, and the unique finlets and caudal keel.
- Raw Fillet: The flesh will be brilliantly white and have a noticeably oily, satiny feel to the touch. In contrast, true albacore (white tuna) has a pinkish tint.
- Cooked Fillet: The buttery, flaky texture and snow-white color remain distinct after cooking, which can help differentiate it from leaner white fish.
Conclusion
Knowing what escolar looks like is essential for both culinary connoisseurs and casual diners. The fish's striking dark exterior, deep-water adaptations, and uniquely rich, white flesh make it stand out. However, its attractive flesh is also the reason for widespread mislabeling in the seafood industry, a practice that can have uncomfortable digestive consequences for consumers due to the fish's indigestible oil content. By being able to recognize the telltale signs of escolar, you can make more informed choices, whether you are ordering sushi or purchasing fillets from a market. For more information on escolar's culinary profile and health considerations, consult reputable sources like the seafood experts at Chefs Resources:(https://www.chefs-resources.com/seafood/finfish/escolar/).
