Melanotaenia splendida splendida · Eastern Rainbowfish

Overview

This Australian rainbowfish varies conspicuously in color and pattern by locality, so Melanotaenia splendida splendida is often sold with a place name attached. Juveniles usually look subdued, and full adult coloration may take more than a year to develop.

Distribution & habitat

Australian habitats include swamps, lagoons, streams, and rivers. Fish commonly stay near aquatic vegetation or submerged wood. Seasonal changes affect temperature, water level, and sediment conditions.

Aquarium setup

Balance dense plants with open swimming space and use slow to moderate flow. Approximately neutral water is appropriate. Decor should offer security without restricting these active fish to narrow gaps.

Diet & feeding

Feeding is straightforward with a variety of suitable dry, frozen, and live foods. Regular live meals help bring out the fish’s coloration.

Behaviour & compatibility

Groups of six to eight or more reduce nervousness and promote male displays, provided the aquarium expands with the group. Although peaceful, its size and brisk movement can disturb tiny or slow neighbors.

Comparable rainbowfishes, characins, danios, barbs, freshwater gobies, and suitable cory catfish are candidates. Separate geographic forms and subspecies within this complex to avoid hybridization.

Sexual dimorphism

Males become larger, brighter, and much deeper-bodied than females, developing longer dorsal and anal fins. Females fill out in the abdomen as spawning approaches.

Breeding

It scatters eggs readily, though the fry require more attention. A bare-bottom breeding tank can hold fine plants or spawning mops, gentle air-powered filtration, and slightly hard alkaline water. Condition adults in a group, then select a full female and a well-colored male. A modest temperature rise may trigger activity.

Daily spawning batches can continue for weeks, with eggs attaching by fine threads. Adults generally do not eat them, but regular transfer to a nursery filled with parental-tank water makes care easier. Eggs hatch after around 7–12 days. Feed infusoria initially, moving to swimming prey such as Artemia nauplii after roughly a week. Fry remain at the surface, so sinking foods are unsuitable.

Notes

Local forms can overlap in appearance. Retain their locality labels and provenance, and breed them separately rather than pairing fish solely by color.