How to Identify White Marlin

To identify White Marlin (Kajikia albida), look at these key features.

Physical Characteristics

Body shape

torpedo

Coloration

Dark blue to blackish-blue dorsally, fading to silvery-white on the flanks and belly. Often exhibits iridescent purple or bronze hues when alive. The first dorsal fin is dark blue to black, while other fins are typically dark brown or blackish.

Scale type

ctenoid

Mouth position

terminal

Distinctive features

Relatively short, rounded bill (rostrum), circular in cross-section., First dorsal fin is rounded, not sharply pointed, and relatively tall., Anal fin is also rounded and similar in shape to the second dorsal fin., Lateral line is prominent and simple, forming a single arch over the pectoral fin., Pectoral fins are broad and rounded at the tips, not rigid and can be folded back against the body.

Dorsal fin

Two dorsal fins. The first dorsal fin is long-based, relatively tall, and distinctly rounded at the apex. It has 28-36 rays. The second dorsal fin is much smaller, located far back on the body, and also rounded.

Tail fin

Deeply forked, lunate caudal fin, characteristic of fast-swimming pelagic fish.

Pectoral fin

Long, broad, and rounded at the tips, consisting of 18-21 rays. They are flexible and can be folded flat against the body.

Distinctive fins

The first anal fin is similar in shape and size to the second dorsal fin, with 13-17 rays. The second anal fin is very small. Pelvic fins are slender and relatively short.

Identification Tips

1. 1

   Bill Shape

   The bill (rostrum) of the White Marlin is relatively short and stout, and distinctly rounded in cross-section, unlike the more compressed bill of the Sailfish or the longer, more pointed bill of the Blue Marlin.

2. 2

   Dorsal Fin

   The first dorsal fin is tall and has a distinctly rounded anterior lobe, which is a key distinguishing feature from other marlin species. It is not as high as a Sailfish's sail, nor as pointed as a Blue Marlin's dorsal fin.

3. 3

   Pectoral Fins

   White Marlin have broad, rounded pectoral fins that are flexible and can be folded back against the body. This contrasts with the rigid, less rounded pectoral fins of the Blue Marlin.

4. 4

   Lateral Line

   The lateral line is simple and forms a single arch above the pectoral fin, which can be visible on fresh specimens.

5. 5

   Body Coloration

   While variable, the overall lighter, silvery-white flanks and belly, contrasting with the dark blue back, are characteristic. Live specimens often show faint vertical bars or spots, which fade quickly after death.

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