Threadfin Rainbow

The threadfin rainbowfish (Iriatherina werneri) comes from northern Australia and southern New Guinea, and it has the most extravagant fins of any small aquarium fish. Mature males carry a tall first dorsal fin and long black filaments trailing from the second dorsal and anal fins, sometimes as long as the body itself. The body is a modest silver-amber with fine dark barring, which lets the fins do the work. Males display by spreading everything at once.

Aquarium care

• A small rainbowfish, gentle and slow-feeding.
• Peaceful, and easily outcompeted for food.
• Keep eight or more with several males so displaying happens.
• Wants calm water with plenty of planting and no strong current.
• Has a very small mouth. It needs micro foods: crushed flake, micro pellets, frozen cyclops and baby brine shrimp.
• Long fins make it a target for nippers.

Best in a quiet planted tank with small rasboras, pygmy corydoras and other gentle nano fish. Avoid barbs, serpae tetras and anything else with a habit of nipping.

Stock rotates with each shipment, and livestock is sold for local pickup at our Lethbridge store. See the current rainbows.