How to Identify Silver Needlefish

To identify Silver Needlefish (Tylosurus acus), look at these key features.

Physical Characteristics

Body shape

elongated

Coloration

Dorsal surface is typically dark blue to greenish-blue, fading to silvery on the sides and white on the belly. A prominent silvery lateral stripe may be present. Fins are generally dusky or translucent.

Scale type

cycloid

Mouth position

terminal

Distinctive features

Extremely elongated, slender body, Long, pointed jaws forming a 'needle-like' snout, with numerous sharp teeth, Dorsal and anal fins located far back on the body, nearly opposite each other, Large eyes, Absence of gill rakers on the first arch

Dorsal fin

Single dorsal fin, positioned posteriorly, with 21-25 soft rays. No spines.

Tail fin

Deeply forked caudal fin, with the lower lobe typically longer than the upper.

Pectoral fin

Relatively short pectoral fins, located low on the body.

Distinctive fins

Pelvic fins are small and abdominal, located far back on the body, well behind the pectoral fins.

Identification Tips

1. 1

   Body Shape and Jaws

   The most striking feature is the very long, slender body and the extremely elongated, pointed jaws, which are characteristic of all needlefish. The jaws are filled with numerous sharp, conical teeth.

2. 2

   Fin Placement

   Both the dorsal and anal fins are set far back on the body, almost directly opposite each other, close to the caudal peduncle. The caudal fin is deeply forked, with the lower lobe often longer.

3. 3

   Coloration

   Look for the dark blue to greenish-blue back, silvery sides, and white belly. A distinct silvery lateral stripe may be present.

4. 4

   Size

   Tylosurus acus is one of the larger needlefish species, reaching lengths of over 1 meter. This helps distinguish it from smaller, similar-looking species.

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