Morphological variation in hybrids between Salmo marmoratus and alien Salmo species in the Volarja stream, Soca River basin, Slovenia

There were significant correlations between colour pattern, LDH-5* genotype and certain meristic characters in 59 hybrid trout Salmo sp. from the Volarja stream, Soca River basin, Slovenia. It is concluded that panmixia between native Salmo marmoratus and introduced S. trutta of Atlantic, Danubian and Mediterranean origin had not been reached in this zone, despite the long period of introgression. The result is in agreement with other studies dealing with introgression in Salmo, and for management purposes certain morphological characters, especially colour pattern, can be a Valuable tool in restoring the marble trout population in the Soca River. (C) 2000 The Fisheries Society of the British Isles.