How to Identify Arapaima

To identify Arapaima (Arapaima gigas), look at these key features.

Physical Characteristics

Body shape

torpedo

Coloration

Dorsally dark greenish-brown to black, fading to a lighter, often reddish-orange hue on the flanks and ventral side, particularly noticeable on the caudal peduncle and tail. The large scales often have a distinct red margin.

Scale type

ganoid

Mouth position

superior

Distinctive features

Large, bony, mosaic-like scales that are extremely tough and provide excellent protection against predators like piranhas., A large, flattened head with a wide, upturned mouth., A modified, vascularized swim bladder that functions as a lung, allowing it to breathe atmospheric air., Prominent red coloration on the caudal peduncle and tail in mature individuals.

Dorsal fin

Long and set far back on the body, almost opposite the anal fin.

Tail fin

Rounded and powerful, providing strong propulsion.

Pectoral fin

Relatively small and positioned low on the body.

Distinctive fins

The dorsal and anal fins are positioned posteriorly, giving the fish a streamlined appearance for powerful bursts of speed.

Identification Tips

1. 1

   Size

   Arapaima gigas is one of the largest freshwater fish, commonly reaching lengths of 2-3 meters (6.6-9.8 feet) and weights over 100 kg (220 lbs). The largest recorded specimens have exceeded 4.5 meters (15 feet) and 200 kg (440 lbs).

2. 2

   Scales

   Its large, tough, bony scales with a distinctive mosaic pattern and often red margins are unique.

3. 3

   Air Breathing

   Regularly surfaces to gulp air, a behavior easily observed and characteristic of the species.

4. 4

   Body Shape and Coloration

   The elongated, torpedo-shaped body with dark dorsal coloration fading to reddish-orange on the posterior flanks and tail is a key identifier.

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