赫氏虹银汉鱼 · Lake Tebera Rainbowfish

Overview

Adult Melanotaenia herbertaxelrodi can show striking color in a planted aquarium with consistently good water. This peaceful but nervous rainbowfish benefits from cover, room to display, and a substantial group of its own kind.

Distribution & habitat

It is restricted to the Lake Tebera drainage in the Central Highlands of Papua New Guinea. Rainforest-covered slopes surround the basin, with marshes and small streams around the lake. The fish uses clear, vegetation-rich parts of both the lake and connected flowing waters.

Aquarium setup

Use a footprint around 90 × 30 cm or larger. Dense planting should be interrupted by open lanes for swimming and male displays. Gentle circulation and weekly partial water changes suit it, with water quality kept consistently high.

Relatively hard, neutral to alkaline conditions are appropriate. Soft, acidic water is unsuitable.

Diet & feeding

This adaptable omnivore accepts most dry, frozen, and live foods. Regular suitable live food helps maintain strong coloration.

Behaviour & compatibility

Choose peaceful, similarly sized companions that share its water requirements. Keep at least six to eight together, allowing more space for larger groups. Conspecific company both reduces skittishness and encourages males to display.

Sexual dimorphism

Males grow larger and brighter, with a much deeper body and longer dorsal and anal fins at maturity.

Breeding

Egg production is relatively straightforward; rearing the young is the more demanding stage. Condition adults as a group, then select a robust pair. Fine plants or spawning mops can collect eggs in a gently aerated breeding setup without substrate. Slightly hard, alkaline water around 22–24 °C is suitable.

Small daily batches may continue for several weeks. Eggs attach by fine threads. Adults generally leave them alone, but regular transfer into matching water simplifies nursery care. Incubation takes about seven to twelve days, depending on temperature. Provide microscopic food initially and introduce small swimming prey, such as newly hatched brine shrimp, after roughly a week. The young remain close to the surface, so sinking foods are unsuitable at this stage.

Notes

Its restricted natural range deserves attention. Excessive collection has been suggested as a possible pressure, but that possibility should not be presented as a confirmed threat classification.