Generally confined to streams that are tributaries to the Adriatic they are found in northern Italy, Slovenia, Croatia, Montenegro and Bosnia-Herzegovina. Their unusual variegated markings on their dorsal area give them their name.
They grow very fast with lengths that vary from 10 up to 25 inches. The largest Marble Trout observed was 46 inches long. These are relatively rare trout due to their rather limited geographical range,
and consequently are on the bucket list for many fishermen.