Description

The Pearl Arowana (Scleropages jardinii):

Species Profile

The Pearl Arowana, also commonly known as the Jardini Arowana or Australian Saratoga, is a highly prized freshwater fish originating from river systems across Northern Australia and New Guinea. Known for its powerful build and distinctive scale patterning, it is a demanding but rewarding species for the experienced aquarist.

Key Statistics and Appearance

Appearance: The Pearl Arowana has a long, torpedo-shaped body and a large, upturned mouth used for surface feeding. Its name comes from the unique “pearling” or spotting on its large, metallic scales. Each scale often displays a striking patch of red, gold, or pink colouring, particularly visible under strong aquarium lighting. It has two prominent sensory barbels extending from its lower jaw.

Aquarium Requirements and Environment

Keeping a Pearl Arowana successfully requires a substantial commitment to space and filtration.

Tank Size and Configuration

Due to their large adult size and need for ample swimming space, the minimum size for a mature specimen is approximately $1000\text{ litres}$. The tank footprint (length and width) is far more important than the height, as these are surface-dwelling fish.

• Lid Security: Arowanas are powerful, notorious jumpers. The aquarium lid must be extremely heavy, tightly secured, and free of any large gaps. A frightened or startled Arowana can easily injure itself or escape.
• Substrate: A fine sand or smooth gravel substrate is acceptable, though it is often easier to maintain bare-bottom tanks to facilitate cleaning.
• Décor: Use large, smooth bogwood or sizeable, rounded rocks to provide territorial markers. Ensure all décor is heavy and stable so it cannot be knocked over. Provide open swimming space in the upper two-thirds of the water column.

Water Parameters

Arowanas are highly sensitive to poor water quality. Consistent maintenance is non-negotiable.

• Temperature: 24∘C−28∘C
• pH Level: Slightly acidic to neutral ($\text{pH }6.5-7.5$)
• Hardness (GH): Soft to Moderately Hard
• Filtration: Due to their size and messy feeding habits, powerful, multi-stage external canister filters (or a large sump system) are mandatory to handle the massive bio-load. Weekly water changes of $25\%$ to $30\%$ are essential.

Diet and Feeding

The Pearl Arowana is a carnivore and an opportunistic predator. While they readily accept live food, it is strongly advised to base their diet on high-quality prepared and frozen foods to ensure balanced nutrition and minimise the risk of disease.

Feed $1-2$ times daily, only offering as much food as the fish can consume within a minute or two. Overfeeding can lead to health issues and further strain the filtration system.

Temperament and Tank Mates

Pearl Arowanas are generally considered to be more aggressive and territorial than their Asian or Silver cousins. They should ideally be kept as a single specimen.

• Intraspecies Aggression: They are highly aggressive towards their own kind and similar-looking fish.
• Interspecies Compatibility: If you must house them with others, tank mates must be too large to be viewed as food, yet robust enough to tolerate the Arowana’s territorial nature. Good options include:
  • Large, peaceful Catfish (e.g., Synodontis or larger Plecos).
  • Large Cichlids (e.g., Flowerhorn or Oscars).
  • Stingrays (in appropriate setups).

Always introduce tank mates while the Arowana is young to allow it to adapt, and ensure the aquarium is large enough to dissipate aggression.