The Leopard Danio is a selectively developed color morph of the iconic Zebrafish (Danio rerio), in which the characteristic horizontal blue and silver stripes are replaced by an irregular pattern of dark, leopard-like spots distributed across a silvery to blue body. Its origins are in selective breeding programs in the ornamental fish industry, though there is some debate as to whether the spotted pattern may have some natural basis. In all other respects — biology, behavior, care requirements, and temperament — the Leopard Danio is identical to the standard Zebrafish. It reaches approximately 5 cm, is entirely peaceful and sociable, and thrives in schools of six or more where it displays confident, active behavior throughout the water column. The Leopard Danio is one of the most forgiving and adaptable aquarium fish available, tolerating a wide range of water conditions, temperatures, and food types. It has been a fixture in the freshwater hobby for decades and remains popular with beginners for its hardiness and with enthusiasts who appreciate its unique spotted livery. A school mixed with standard Zebrafish creates an attractive display of striped and spotted individuals.