Irwini Catfish (8–10 cm) – Detailed Product Description

• General Overview

  • The Irwini Catfish (often referred to as Irwini or Irvine’s catfish in the aquarium trade) is a striking freshwater river catfish known for its elongated body, strong swimming ability, and impressive adult size.

  • Offered here at 8–10 cm, this specimen is a healthy juvenile stage, ideal for experienced aquarists who want to raise a large predatory-style catfish from a young age.

  • This species is highly valued for its active behavior, bold presence, and riverine appearance, making it a standout fish in large display aquariums.

• Appearance & Physical Characteristics

  • Long, streamlined body built for swimming in strong currents.

  • Smooth, scaleless skin typical of large river catfish species.

  • Well-developed barbels (whiskers) used for navigation and food detection.

  • Juveniles display a sleek, understated coloration that becomes more pronounced and impressive as they mature.

  • Strong tail fin and muscular body indicate its fast growth potential and active nature.

• Temperament & Natural Behavior

  • Semi-aggressive by nature due to its size and predatory instincts.

  • Not territorial in the traditional sense, but may consume smaller tank mates as it grows.

  • Highly active swimmer compared to many bottom-dwelling catfish.

  • Prefers open swimming space rather than constant hiding.

  • Best appreciated in large aquariums where its movement and behavior can be fully observed.

• Adult Size & Growth Rate

  • Adult size: Can exceed 60–80 cm (depending on species and conditions).

  • Growth rate: Fast under optimal conditions.

  • Requires long-term planning—this is not a fish for small or medium aquariums.

  • Juvenile size (8–10 cm) allows for easier acclimation and monitoring during early growth stages.

• Water Conditions (Critical for Health & Growth)

  • Temperature: 24–30 °C

  • pH range: 6.0–7.5

  • Water hardness: Soft to moderately hard (3–15 dGH)

  • Requires excellent filtration due to heavy waste production.

  • Strong water movement and high oxygen levels are highly recommended to mimic natural river habitats.

  • Weekly water changes of 30–40% are strongly advised.

  • Sensitive to ammonia and nitrite—an established tank is essential.

• Tank Size & Setup

  • Minimum tank size (juvenile): 200 liters, with rapid upgrades required.

  • Long-term tank size: Very large aquarium or indoor pond setup.

  • Wide, long tanks are preferred over tall tanks.

  • Use sand or smooth substrate to protect the belly.

  • Decor should be minimal and sturdy—rocks, large driftwood, and open swimming areas.

  • Avoid sharp decorations that may injure the fish during fast swimming.

• Feeding Habit & Diet

  • Carnivorous to omnivorous, leaning strongly toward protein-based foods.

  • Juveniles should be fed regularly to support growth.

  • Recommended foods include:

    • High-quality sinking carnivore pellets

    • Frozen foods (shrimp, fish fillet, mussels, earthworms)

    • Occasional live foods (where legal and safe)

  • Feed once daily or every other day as it grows to avoid obesity.

  • Uneaten food must be removed promptly to maintain water quality.

• Tank Mates & Compatibility

  • Suitable only with large, robust fish that cannot be swallowed.

  • Compatible tank mates may include:

    • Large catfish species

    • Large cichlids

    • Arowana

    • Pacu or other large characins

  • Not suitable for small fish, shrimp, or delicate species.

  • Best kept as a single specimen unless housed in extremely large systems.

• Care Level & Aquarist Suitability

  • Care level: Advanced

  • Recommended for experienced aquarists familiar with large fish husbandry.

  • Requires commitment to tank upgrades, filtration, and long-term maintenance.

  • Not suitable for beginners or casual aquarium keepers.

• Longevity & Commitment

  • Can live 10–15 years or more with proper care.

  • A true long-term aquarium resident.

  • Responsible ownership is essential due to its eventual size and needs.

• Why Choose the Irwini Catfish (8–10 cm)?

  • Rare and impressive river catfish species

  • Strong growth potential and commanding presence

  • Ideal for large display aquariums

  • Active swimmer with bold behavior

  • Perfect for serious collectors of large freshwater fish

The Irwini Catfish (8–10 cm) is a powerful and rewarding species for aquarists ready to commit to large-scale fishkeeping. With proper space, nutrition, and water quality, this catfish will grow into a truly magnificent centerpiece fish.