How to Identify Golden Pencilfish

To identify Golden Pencilfish (Nannostomus beckfordi), look at these key features.

Physical Characteristics

Body shape

elongated

Coloration

The base body color ranges from golden-brown to reddish-brown, often with a distinct dark horizontal stripe running from the snout through the eye to the caudal peduncle. Above this stripe, there is often a lighter, sometimes iridescent, golden or reddish stripe. The belly is typically lighter. Fins are generally hyaline (clear) but can show hints of red or yellow, especially in males during breeding. Some populations exhibit more pronounced red or orange pigmentation.

Scale type

cycloid

Mouth position

superior

Distinctive features

Slender, torpedo-shaped body, Prominent dark horizontal stripe, Small, upturned mouth, Sexual dimorphism: males are generally more slender, intensely colored, and may have more red in their fins, especially the anal fin, which can be slightly elongated and more pointed than in females. Females are typically rounder in the belly, especially when gravid.

Dorsal fin

Small, located mid-body, typically with 2 unbranched and 7-8 branched rays.

Tail fin

Forked, with symmetrical lobes.

Pectoral fin

Small, located low on the body.

Distinctive fins

Adipose fin is absent, a characteristic of the family Lebiasinidae. The anal fin is relatively short, with 2 unbranched and 8-9 branched rays. Pelvic fins are small.

Identification Tips

1. 1

   Body Shape and Size

   Elongated, slender body, typically reaching a maximum standard length of 3.5-4 cm (1.4-1.6 inches).

2. 2

   Coloration Pattern

   Distinguished by a prominent dark lateral stripe running from the snout to the caudal fin, often with a golden or reddish stripe above it. The intensity of these colors can vary.

3. 3

   Mouth Position

   Small, upturned mouth, indicative of its surface-feeding habits.

4. 4

   Fin Structure

   Absence of an adipose fin and relatively small, clear fins.

Explore Golden Pencilfish