How to Identify Common Silver-biddy

To identify Common Silver-biddy (Gerres setifer), look at these key features.

Physical Characteristics

Body shape

compressed

Coloration

Overall silvery, often with faint dusky vertical bars on the upper flanks, which may fade after capture. Fins are hyaline (transparent) to dusky.

Scale type

ctenoid

Mouth position

terminal

Distinctive features

Highly protrusible mouth, forming a downward-pointing tube when extended., Second dorsal fin spine significantly elongated, often reaching or extending beyond the caudal fin base in adults., Deeply forked caudal fin., Large, deciduous scales.

Dorsal fin

Single dorsal fin with 9 spines and 10-11 soft rays. The second dorsal spine is notably elongated.

Tail fin

Deeply forked caudal fin.

Pectoral fin

Long and pointed pectoral fins.

Distinctive fins

Pelvic fins are thoracic, with 1 spine and 5 soft rays. Anal fin has 3 spines and 7-8 soft rays.

Identification Tips

1. 1

   Elongated Second Dorsal Spine

   The most reliable distinguishing feature is the exceptionally long second spine of the dorsal fin, which is much longer than any other dorsal spine and often extends past the caudal fin base.

2. 2

   Protrusible Mouth

   Observe the mouth, which can be extended significantly downwards to form a tube for feeding on benthic organisms.

3. 3

   Body Coloration

   Silvery body with a compressed, oval shape. Faint dusky bars may be visible on the upper flanks, especially when alive.

4. 4

   Scale Size

   Possesses relatively large, easily detached (deciduous) scales.

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