The grayling’s mouth is small, just like its teeth. It measures about 30 cm and weighs 200-300 gr. It rarely exceeds 50 cm and a 1kg weight.
Clear, well-oxygenated rivers and streams, not too rapid, and with a stony or gravel bed, represent the favorite habitat of the grayling. It feeds on insects and small aquatic and terrestrial invertebrates.
The grayling naturally populates watercourses from central-northern Europe to southern Italy; it was introduced also in the region of the Tagus River, Spain, and Scotland.