Lake Tebera Rainbowfish - Melanotaenia Herbertaxelrodi

Lake Tebera Rainbowfish | A Rare Highland Gem From Papua New Guinea

The Lake Tebera Rainbowfish (Melanotaenia herbertaxelrodi) is one of the most beautiful and underappreciated rainbowfish in the freshwater aquarium hobby. Endemic exclusively to Lake Tebera — a remote highland lake nestled in the Central Highlands of Papua New Guinea at roughly 800 metres above sea level — this rare and striking fish is prized for its brilliant colouration: a vivid yellow-gold body with a shimmering greenish tinge, a bold bluish-to-black mid-lateral stripe running the length of the body, and yellow to red dorsal, anal, and caudal fins that intensify dramatically in breeding males. Large males develop a noticeably deep, laterally compressed body and extended finnage that make them one of the most impressive medium-sized rainbowfish available.

Still relatively uncommon in the hobby outside of dedicated rainbowfish enthusiasts, the Lake Tebera Rainbowfish is a genuinely special find — and in a large school under good lighting, it is a breathtaking display.

Lake Tebera Rainbowfish Care Guide

Care at a Glance

• Scientific name: Melanotaenia herbertaxelrodi
• Also known as: Lake Tebera Rainbowfish, Yellow Rainbowfish, Herbert Axelrod's Rainbowfish
• Origin: Lake Tebera basin, Central Highlands, Papua New Guinea — endemic
• Adult size: up to 4.7 inches (12 cm) — males noticeably larger and more colourful than females
• Minimum tank size: 25 gallons (95 litres) for a small group — longer tanks strongly preferred
• Temperature: 68–79°F (20–26°C) — a cooler highland species; best colour displayed at the lower end of this range
• pH: 7.5–7.8 — slightly alkaline water essential
• Hardness: 8–15 dGH — moderately hard water preferred
• Best kept in groups of 6–8 or more, with a ratio of 1 male to 2 females
• Lifespan: 3–5 years with good care

Lake Tebera Rainbowfish Tank Setup

A well-planted aquarium with open central swimming space, gentle to moderate water flow, and slightly hard, alkaline water suits these fish perfectly — reflecting the clear, cool, vegetated conditions of their highland lake home. Dense planting along the sides and background with Vallisneria, Java Fern, Anubias, and floating plants provides structure and security, while the open centre gives males room to display and the school room to move together. Dark substrate helps bring out the warmth of their yellow-gold colouration beautifully.

Regular weekly partial water changes are strongly recommended — consistent water quality is key to keeping their colouration at its most vivid and their health robust.

Feeding Your Lake Tebera Rainbowfish

Omnivores with a healthy appetite. A high quality flake or small pellet forms an excellent staple diet, supplemented generously with frozen or live foods such as bloodworm, brine shrimp, daphnia, and small insects. A varied, protein-rich diet will bring out the full intensity of male colouration — particularly the deep yellow and red tones in the fins.

How Many Lake Tebera Rainbowfish Should You Keep?

These are a true shoaling species and should always be kept in groups of 6 or more. Males in the presence of other males will display their most vivid and intense colouration as they compete for female attention — the difference between a single male and a proper group is remarkable. A ratio of one male to two females reduces competition and stress while producing the best overall display.

Lake Tebera Rainbowfish Tank Mates

• Other peaceful rainbowfish of similar size
• Larger tetras, barbs, and danios
• Corydoras and peaceful bottom dwellers
• Freshwater gobies and similar community species
• Due to their preference for slightly hard, alkaline water, they can be kept alongside some Rift Lake cichlid species in appropriately sized setups
• Avoid soft water species that require acidic conditions — water chemistry compatibility is essential
• Avoid fin-nipping species and slow-moving, long-finned fish that may be stressed by their active nature