How to Identify Threadfin Catfish

To identify Threadfin Catfish (Nemapteryx nelsoni), look at these key features.

Physical Characteristics

Body shape

elongated

Coloration

Dorsal surface typically dark grey to brownish, fading to a lighter, silvery-white on the ventral side. Fins are often dusky or translucent.

Scale type

none

Mouth position

terminal

Distinctive features

Elongated, slender body typical of ariid catfishes., Two prominent barbels on the upper jaw (maxillary barbels) that extend beyond the eye., A pair of smaller mental barbels on the chin., Dorsal fin with a strong, serrated spine and a prolonged, filamentous ray., Pectoral fins also possess strong, serrated spines and often have a prolonged filament., Adipose fin present, small., Caudal fin deeply forked.

Dorsal fin

I, 7; first ray is a strong, serrated spine, followed by 7 soft rays, with the first soft ray often greatly elongated into a filament.

Tail fin

Deeply forked, with pointed lobes.

Pectoral fin

I, 10-12; first ray is a strong, serrated spine, often with a prolonged filament.

Distinctive fins

The prolonged filamentous extensions on the dorsal and pectoral fins are key distinguishing features.

Identification Tips

1. 1

   Fin Filaments

   Look for the characteristic long, thread-like extensions on the dorsal and pectoral fins. These are often longer in juveniles and can be broken in older specimens.

2. 2

   Body Shape and Coloration

   Its elongated, silvery-grey body with a darker dorsal surface and lighter belly is typical. The absence of scales is also a key catfish trait.

3. 3

   Barbels

   Observe the two long maxillary barbels extending past the eye and the smaller mental barbels on the chin.

4. 4

   Caudal Fin

   The deeply forked tail fin is a good identifier among ariid catfishes.

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