How to Identify Atlantic Bonito

To identify Atlantic Bonito (Sarda sarda), look at these key features.

Physical Characteristics

Body shape

torpedo

Coloration

Dorsal side is dark metallic blue to blue-green, fading to silvery white on the flanks and belly. Distinctive dark, oblique stripes (typically 5-11) run dorsally from the lateral line towards the back, angled upwards and backwards. These stripes are a key identification feature.

Scale type

none

Mouth position

terminal

Distinctive features

Streamlined, fusiform body, 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), Two dorsal fins, closely set, Series of finlets behind the second dorsal and anal fins, Strongly forked caudal fin, Conical teeth in a single row in both jaws

Dorsal fin

Two dorsal fins; the first is long with 19-23 spines, deeply notched, and the second is much shorter with 13-18 soft rays, followed by 7-9 finlets. The two fins are very close together, almost touching.

Tail fin

Strongly forked (lunate) caudal fin, characteristic of fast-swimming pelagic fish, with a prominent median keel on the caudal peduncle and two smaller keels on either side.

Pectoral fin

Short, triangular pectoral fins, typically with 23-26 rays. Located low on the body.

Distinctive fins

Pelvic fins are small and located beneath the pectoral fins. Anal fin has 14-17 soft rays, followed by 6-8 finlets. The finlets are crucial for reducing drag during rapid swimming.

Identification Tips

1. 1

   Body Shape and Coloration

   Look for the torpedo-shaped body, dark blue-green back, silvery sides, and especially the distinctive dark, oblique stripes running upwards and backwards from the lateral line on the dorsal half of the body.

2. 2

   Scales

   Note the absence of scales on most of the body, except for the well-developed corselet around the pectoral fins.

3. 3

   Finlets

   Count the finlets behind the second dorsal and anal fins (7-9 dorsal, 6-8 anal). This is a key characteristic of scombrids.

4. 4

   Teeth

   Observe the conical, relatively large teeth in a single row in both jaws, indicative of its predatory diet.

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