Origin and Appearance

Native to Australia and New Guinea’s freshwater and brackish streams, the Pacific Blue-eye (Pseudomugil signifer) grows to 3-4 cm (1.2-1.6 inches). Its slender body displays iridescent bluish-green hues with golden scales and delicate, elongated fins that shimmer under light. The namesake brilliant blue eyes make it a standout in any nano or community setup.

Ideal Tank Setup

Provide a minimum 38L (10-gallon) tank for a school of 6-8 to encourage natural schooling behavior. Use fine sand or smooth gravel substrate, dense plants for cover, driftwood, and floating vegetation to mimic their shaded habitat. Gentle filtration with 4-5x turnover and subdued lighting promotes activity while reducing stress. Avoid strong currents.

Planted nano tank with Pacific Blue-eyes schooling near floating plants.​

Water Parameters

Stable conditions are key for beginners: maintain 20-26°C (68-79°F), pH 6.5-7.5, and GH 5-15 dGH. Perform 25% weekly water changes to keep nitrates low. These adaptable fish tolerate freshwater but appreciate slight flow and oxygenation.

Feeding Guide

Omnivorous and easy to feed, offer high-quality flakes or micro pellets as staple. Supplement 2-3 times weekly with live or frozen daphnia, brine shrimp, or bloodworms for color and health. Feed small amounts 2x daily to avoid waste.

Temperament and Tank Mates

Peaceful and active, they shine in schools but may hide if alone. Pair with nano tetras, rasboras, or shrimp in community tanks. Avoid fin-nippers or aggressive species.

Breeding Tips for Beginners

Scatter eggs among fine-leaved plants or moss; adults rarely eat fry. Use infusoria or liquid food initially, then brine shrimp nauplii. Separate fry for best survival in a mature tank.