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 Vola rja stream, Soca River basin, Slovenia. It is concluded that panmixia betwe en native Salmo marmoratus and introduced S. trutta of Atlantic, Danubian a nd Mediterranean origin had not been reached in this zone, despite the long period of introgression. The result is in agreement with other studies dea ling with introgression in Salmo, and for management purposes certain morph ological characters, especially colour pattern, can be a Valuable tool in r estoring the marble trout population in the Soca River. (C) 2000 The Fisher ies Society of the British Isles.