The natural range of the zebrafish is centred around the Ganges and Brahmaputra river basins in north-eastern India, Bangladesh and Nepal.They have typically been described as inhabiting slow-moving or standing water bodies, the edges of streams and ditches, particularly adjacent to rice-fields.There is a wide range of temperatures within the natural range of zebrafish, from as low as 6 °C in winter to over 38 °C in summer.

Spence, R., Gerlach, G., Lawrence, C. and Smith, C. (2008), The behaviour and ecology of the zebrafish, Danio rerio. Biological Reviews, 83: 16/17.