It is characterized by a distinctive marbled color pattern and high growth capacity. The marble trout is found in only handful drainages and rivers of the Adriatic basin in Italy, Slovenia, Croatia, Bosnia and Herzegovina and Montenegro.
The marble trout has a long, cylindrical body, slightly compressed laterally, with a large head (22–25% of the body length). The most obvious characteristic of the marble trout is its marble pattern. The intensity of colour varies considerably upon the surroundings.
Its average size is 30–70 cm. The marble trout feed mainly on smaller fish and benthic invertebrates. Its natural habitat is rivers with a summer temperature of 15 °C (59 °F).
It suffers numerous threats to its existence throughout its range, these include hybridisation with foreign trout species stocked for angling and water extraction and pollution.