Electrophoretic identification and comparative examination of naturally occurring F 1 hybrids between brown trout ( Salmo trutta L.) and atlantic salmon ( S. salar L.)

Abstract

1. 1. Identification of naturally occurring F 1 hybrids between brown trout and Atlantic salmon from the catchment of Lough Neagh, N. Ireland was achieved on the basis of phosphoglucose isomerase zymograms, hybrids displaying summation of parental phenotypes. 2. 2. Hybrids so identified were further examined for a range of enzymes, among which a single locus ( SOD) displayed suspected intermediacy of parentalpatterns. 3. 3. At the majority of loci hybrids were not distinguishable due to possession of polymorphisms in common with either or both parental species, or shared expression of invariant electrophoretic patterns. 4. 4. Hybridisation averaged 0.4% among lake and river caught samples of brown trout, though values reached 5.9% locally.