Red-tailed (Locality Form)

Overview

A locality form from certain river systems in which the caudal and paired fins take on a reddish or orange tinge. Not a separate species, but popular among collectors as a rare regional variant.

Appearance

Shared with the species: Silver Arowana

Silver Arowanas have a distinctive elongated torpedo-shaped body covered in large, silver, metallic-shining scales that can reach several centimeters in width. The mouth is large, upturned, and equipped with a bony structure and two prominent chin barbels used to detect prey. The dorsal and anal fins are long and extend toward a powerful tapering tail fin, giving the fish a streamlined, almost prehistoric appearance. The eyes are positioned high on the head for scanning the water surface and detecting prey from above.

Care

Shared with the species: Silver Arowana

Silver Arowanas require an extremely large aquarium—a minimum of 950 liters (250 gallons) for a single adult—with a very secure, heavy lid to prevent jumping. Water temperature should be maintained at 23–28°C with pH 6.0–7.5 and hardness 2–15 dGH. Strong filtration is essential to manage the high bioload of this large predator. The aquarium should have minimal decorations to allow free swimming, and regular water changes of 20–25% weekly are critical. Juveniles grow approximately 5 cm per month under optimal conditions and should never be kept in small tanks even when young.

Feeding

Shared with the species: Silver Arowana

Silver Arowanas are obligate carnivores requiring substantial protein-rich meals. In the wild they consume fish, crustaceans, insects, frogs, and occasionally small birds or mammals. In captivity they can be fed large insects such as crickets and mealworms, earthworms, shrimp, fish strips, and large pellets specifically formulated for arowanas. Live feeder fish can be offered occasionally but carry disease risks. Juveniles should be fed two to three times daily while adults can be fed every one to two days.

Compatibility

Shared with the species: Silver Arowana

Silver Arowanas are generally peaceful with fish too large to be swallowed, but can be aggressive toward similarly-sized surface dwellers. Suitable tankmates for adults include large, robust species such as large plecos, large cichlids, bichirs, freshwater stingrays, and gars occupying the middle and lower water column. Avoid keeping with small fish, as these will be treated as prey. Two or more arowanas in the same aquarium establish a strong pecking order and require an extremely large tank.

Breeding

Shared with the species: Silver Arowana

Breeding Silver Arowanas in captivity is exceptionally rare and practically impossible in home aquariums. They are paternal mouthbrooders; after spawning, the male collects the large eggs (up to 2.5 cm diameter) and incubates them in his mouth for approximately 50–60 days. Females produce relatively few eggs—usually only a few dozen per spawning. Commercial breeding takes place in large outdoor ponds in Southeast Asia and South America. Captive breeding requires enormous space and near-perfect simulation of natural seasonal changes.

Fun facts

Shared with the species: Silver Arowana

The Silver Arowana is known as the 'dragon fish' in several Asian cultures and is believed to bring prosperity and good luck; large specimens are considered valuable status symbols. These fish possess a swim bladder that functions as a primitive lung, allowing them to breathe air directly from the surface—an ancient adaptation. Baby Silver Arowanas hatch with a large yolk sac attached to their belly that nourishes them for the first several weeks of life while they remain sheltered in their father's mouth.