How to Identify Little Tunny

To identify Little Tunny (Euthynnus alletteratus), look at these key features.

Physical Characteristics

Body shape

torpedo

Coloration

Dorsal side dark blue to blue-black, often with wavy, dark longitudinal stripes or 'worm-like' markings above the lateral line. Ventral side silvery-white. A distinctive pattern of 3-7 dark spots (often 4-5) is present between the pectoral and pelvic fins, below the lateral line.

Scale type

none

Mouth position

terminal

Distinctive features

Robust, fusiform body, slightly compressed laterally., Two dorsal fins, widely separated. The first dorsal fin has 10-15 spines, the second has 11-15 soft rays followed by 8-9 finlets., Anal fin with 11-15 soft rays followed by 6-8 finlets., Pectoral fins short, not reaching the interspace between the dorsal fins., Caudal fin deeply forked with a slender caudal peduncle and a prominent central keel flanked by two smaller keels., Small, conical teeth in a single row in both jaws., Absence of scales on the body except for the corselet (a patch of large, thick scales around the pectoral fin and along the lateral line) and the lateral line itself., Distinctive dark spots (3-7) below the pectoral fin.

Dorsal fin

Two dorsal fins, widely separated. First dorsal fin with 10-15 spines, second dorsal fin with 11-15 soft rays followed by 8-9 finlets.

Tail fin

Deeply forked caudal fin with a slender caudal peduncle and a prominent central keel flanked by two smaller keels.

Pectoral fin

Short, not reaching the interspace between the dorsal fins, with 25-29 rays.

Distinctive fins

8-9 dorsal finlets and 6-8 anal finlets posterior to the soft dorsal and anal fins, respectively.

Identification Tips

1. 1

   Body Shape and Coloration

   Look for a robust, torpedo-shaped body with a dark blue-black back and wavy, 'worm-like' markings above the lateral line. The belly is silvery-white.

2. 2

   Pectoral Fin Spots

   The most reliable distinguishing feature is the presence of 3-7 (usually 4-5) distinct dark spots located between the pectoral and pelvic fins, below the lateral line. These spots are absent in other similar species.

3. 3

   Dorsal Fins

   Note the two widely separated dorsal fins. The first dorsal fin is tall and spiny, while the second is shorter and followed by finlets.

4. 4

   Scales

   Observe the absence of scales on most of the body, except for a prominent corselet around the pectoral fin and along the lateral line.

5. 5

   Size

   Little Tunny are generally smaller than most other tuna species, typically reaching a maximum fork length of about 100 cm (39 inches) and a weight of 10-15 kg (22-33 lbs), though most commonly encountered specimens are smaller.

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