Scarlet Gem Badis (Dario hysginon)

The Scarlet Gem Badis (Dario hysginon) is a small, brilliantly colored fish from shallow, slow-moving streams and marginal vegetation in Myanmar and northeastern India. Males are stunning, displaying a mosaic of vivid scarlet-red, iridescent blue, and orange on a vertically banded body — colors that become most intense during breeding displays. Females are drab brown, significantly smaller, and easily distinguished.

This species belongs to the family Badidae and grows to only 2–3 cm, making it one of the smallest ornamental fish available. Despite its tiny size, the Scarlet Gem Badis has a bold, inquisitive personality. Males are territorial toward each other but generally peaceful toward other species. They establish small feeding and resting territories in planted nano tanks.

As a micro-predator, Dario hysginon feeds primarily on live and frozen small invertebrates — it often refuses dry food entirely, especially initially. Baby brine shrimp, micro worms, daphnia, and similar live or frozen micro foods are essential for their diet. This feeding requirement makes them more demanding than many nano fish.

They are cave-breeding fish, with males guarding eggs laid in small caves or dense plant cover. The species thrives in soft to moderately hard water with gentle flow and dense planting for territory establishment and cover.

Water Parameters: pH 6.0–7.5, temperature 16–24°C. They are from cool mountain streams and prefer cooler water than many tropical fish. Soft to moderately hard water (GH 2–15) is acceptable. They are sensitive to poor water quality and benefit from stable parameters.

Tank Setup: Nano aquarium of 20–40 liters for a pair or small group. Dense planting with mosses, fine-leafed plants, small caves (coconut shells, small clay pots), and driftwood create ideal conditions. Keep only one male per tank unless the setup is very large with clear visual barriers. Gentle sponge filtration.

Feeding: Micro-predator that often refuses dry food. Feed live or frozen baby brine shrimp, micro worms, cyclops, daphnia, and similar small invertebrates. Some individuals can be trained to accept frozen foods. Feed 2x daily in tiny amounts. Starvation risk if only dry food is offered.

Tankmates: Keep with other very small, peaceful nano fish that won't outcompete them for food: microrasboras (Boraras sp.), small ricefish, dwarf shrimp (adults are safe). Avoid any active, competing, or predatory species. One male per tank.

Breeding: Cave spawners. Males guard eggs in small caves until hatching. Fry are tiny and require infusoria and micro-brine shrimp nauplii. Remove female after spawning to prevent male aggression.