Leopard Danio (Danio frankei)

The Leopard Danio (Danio frankei) is a color variant of Danio rerio (the Zebra Danio), produced through selective breeding or natural mutation, in which the characteristic horizontal stripes are broken into irregular dark spots scattered across the silver body — creating a spotted 'leopard' pattern. Whether this represents a true separate species or a variant of D. rerio has been debated taxonomically, but it is commonly maintained as a separate species designation in the aquarium trade.

In behavior, hardiness, and care requirements, the Leopard Danio is essentially identical to the Zebra Danio — one of the hardiest, most adaptable, and most widely kept freshwater aquarium fish in the world. The energetic, relentlessly active schooling behavior of danios is fully expressed in the Leopard variety.

Males are slightly slimmer and more vibrantly spotted; females are larger and rounder when gravid. Both reach approximately 5–6 cm. Like Zebra Danios, Leopard Danios are egg scatterers that broadcast adhesive eggs among fine-leaved plants or gravel, providing no parental care.

Leopard Danios are favored for their ease of care, tolerance of a wide range of water conditions, and lively, perpetually active behavior that brings constant movement to any aquarium.

Leopard Danios are among the most adaptable freshwater fish: pH 6.0–8.0, hardness 5–20 dGH, and temperatures 15–27°C. Their broad temperature tolerance includes relatively cool water, making them suitable for unheated tanks in many indoor environments.

A minimum 60-liter aquarium with good horizontal swimming space suits a group of 8–10. Provide moderate to strong current via good filter flow or powerhead — they are active, fast swimmers that appreciate flow. Dense plantings around the tank periphery with open central space is ideal. A tight lid is important as they jump readily.

Feed quality flake food, micro pellets, and live or frozen supplements: daphnia, brine shrimp, bloodworms, and micro worms. They are enthusiastic, competitive feeders that accept virtually all standard aquarium foods.

Leopard Danios are entirely peaceful with most community fish. Avoid very long-finned, slow-moving species (bettas, fancy angelfish) that may be stressed by their constant activity. Suitable with tetras, barbs, corydoras, rasboras, gouramis, and most medium community fish.

Keep in groups of at least 8 for natural schooling behavior. Weekly water changes of 25–30% maintain water quality.