The existence of two races of Atlantic salmon (Salmo salar L.) in the British Isles

Abstract

Sera from approximately 10 000 Atlantic salmon collected from rivers in the British Isles have been analysed. Polymorphism at the transferrin locus was observed and the distribution of the transferrin alleles provides further evidence supporting the presence of two races of salmon first postulated by Payne et al. (1971a).

Protein variation and duplicate loci in the Atlantic salmon,Salmo solarL.

“…Designation of enzymes by sub-cellular location also makes inter-specific comparison easier. Of the gene markers detected in the present study, Me m -2, Aat s -2, Sdh-1 and 2 and Idh-3 should prove most useful in population studies since at these loci the frequency of the common allele is less than 0-9, while Mdh B -3 and/or 4, Ada-2, Glo and additionally Tf (Child et al 1976) may be of more limited use because of the high frequency of the common allele. The close similarity of Idh-3 frequencies between the 1977 sample of parr and a sample of adults taken at the mouth of the River Blackwater in 1975 suggests that, at least for the ldh locus, allele frequencies are relatively constant over generations (Table 4).…”

“…Payne, Child & Forrest (1971) showed that while all Salmo salar populations examined shared a common allele (Tfj) at the transferrin locus, two alleles (Tf 3 and Tf t ) occurred only in salmon of North American origin, while another rare allele (Tf%) was specific to European salmon. Variation in the frequency of Tf 2 indicated the presence of two races of Salmo salar in the British Isles, a north-western and western Boreal race and a south-western and southern 'Celtic' race (Payne et al 1971;Child, Burnell & Wilkins, 1976). The transferrin polymorphism has also proved useful in demonstrating differences between populations of salmon from different rivers in eastern North America (MMler, 1970;Payne, 1974).…”

“…Transferrins: Data for the polymorphic Tf locus has been published for the Blackwater population by Child et al (1976). Allele frequencies are given in Table 3.…”

Use of multiple markers demonstrates a cryptic western refugium and postglacial colonisation routes of Atlantic salmon (Salmo salar L.) in northwest Europe

“…However, the allozyme studies of Verspoor (1986), Ståhl (1987) and Bourke et al (1997) have been brought into question by the revelation that a commonly used isoenzyme (ME-2, mMEP-2*) is likely to be acting under selection pressures (Verspoor and Jordan, 1989;Bourke et al, 1997) and as such is not a suitable marker for phylogeographic studies. This may also be the case for transferrin (Verspoor and Jordan, 1989) as used by Payne et al (1971) and Child et al (1976) in the initial investigations.…”

“…This is particularly marked for France and England-a maximum of five samples from across the region were included in studies by Bourke et al (1997) and Verspoor et al (1999). In the only studies to focus directly on this region, Payne et al (1971) and Child et al (1976) described two lineages based on polymorphisms at the transferrin locus. The so-called 'Boreal' lineage radiated from a glacial lake in the southern North Sea and was proposed to occupy most of northern Europe, including the Baltic, while the 'Celtic' race was confined to the southwest of England (UKSouthwest).…”