How to Identify Permit

To identify Permit (Trachinotus falcatus), look at these key features.

Physical Characteristics

Body shape

compressed

Coloration

Silvery body, often with a yellowish or golden wash on the belly and fins. Dorsal and anal fins are typically dark, sometimes black, especially at the anterior lobes. Juveniles may have faint vertical bars.

Scale type

cycloid

Mouth position

terminal

Distinctive features

Deeply forked caudal fin with long, slender lobes., Prominent, sickle-shaped dorsal and anal fins, particularly in adults., Relatively small mouth., Absence of scutes along the lateral line (distinguishing feature from many other jacks).

Dorsal fin

Two dorsal fins; the first with 5-6 short, stout spines, the second with 1 spine and 18-20 soft rays. The anterior lobe of the second dorsal fin is greatly elongated and sickle-shaped in adults.

Tail fin

Deeply forked, with long, slender, and pointed lobes.

Pectoral fin

Short and pointed.

Distinctive fins

The elongated, sickle-shaped anterior lobes of the dorsal and anal fins are highly characteristic, becoming more pronounced with age.

Identification Tips

1. 1

   Body Shape and Coloration

   Look for a deep, compressed, silvery body. The yellowish wash on the belly and fins, and the dark, sickle-shaped dorsal and anal fin lobes are key.

2. 2

   Fin Morphology

   The most definitive feature is the extremely elongated, sickle-shaped anterior lobes of the second dorsal and anal fins, especially in larger individuals. The deeply forked caudal fin is also characteristic.

3. 3

   Lateral Line

   Unlike many other jacks, Permits lack prominent scutes (bony plates) along the lateral line, which feels smooth to the touch.

4. 4

   Mouth

   They have a relatively small, terminal mouth, adapted for picking small invertebrates from the substrate.

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