The diversity and distribution of mtDNA haplotypes in Atlantic salmon (Sulmo sulur L.) from 13 river systems across the species' European range was investigated. Salmon were screened by agarose electrophoresis for variation in a 1400 base pair fra

No abstract

Genetic analysis of the four Trisopterus (Gadidae) taxa suggests that the interrelationships of the two morphs of poor cod (T. minutus minutus in the Atlantic and T. minutus capelanus in the Mediterranean) should be reconsidered. The Mediterranean poor cod T. m. capelanus is more closely related to bib T. luscus than to the Atlantic poor cod, so the population structure in the Atlantic and Mediterranean poor cod must be considered separately. Among 635 Atlantic individuals there was some evidence of poor cod population differentiation (allele frequency heterogeneity test Pc0·0005; F ST =0·0135, Pc0·0005). Levels of genetic variation were similar to those reported for related gadoid species. Some differentiation was present on the Norwegian coast (samples from Trondheimsfjord) and between the Faeroe Islands (Faeroe Bank) and the adjacent European coastal location. In contrast no statistically significant population differentiation was evident in Mediterranean poor cod, but fewer samples and individuals were screened. 2000 The Fisheries Society of the British Isles

This study aimed to increase the number of allozyme loci which may be screened in the Atlantic salmon, Salmo salar L, particularly for use in investigating interactions between wild populations and reared strains. Three samples of wild salmon from Ireland, Scotland and Spain and one from a farmed strain of Norwegian origin were used as index samples. Other Irish samples were used in technique development. Ninety-one enzyme loci were resolved, including 21 not previously screened in S. salar. Thirteen loci were found to be variable, including three novel polymorphic loci (EST5*, FBALD3* and TPI3*). Two novel alleles (sAAT1,2*13O and sAAT3*83) were also detected. Levels of variability were lowest in the Spanish sample. The farmed strain had levels of H and P lower than those in the two other wild samples. Mean levels of H and P were higher than those reported previously in studies that used a smaller number of loci but confirm S. salar as one of the less variable salmonids. Nine of the 13 variable loci showed significant population differentiation, the most discriminatory being mMEP2*. The discriminatory power of the novel variable loci was in the middle of the range of those of the other loci. D values reflected the relative geographical locations from which the samples originated. There were significant dines in allele frequencies at mMEP2* and TPI3*. Fourteen enzyme loci including six variable loci were resolved in adipose fin.

Atlantic salmon, Salmo salar L., from four European locations show allelic variation at one of three triose-phosphate isomerase (TPI) loci (TPI-3*) when separated on horizontal starch gel electrophoresis, using either eye or liver extracts. Two common alleles (*100 and *103) and one rare allele (*97) segregate at TPI-3* with unambiguous typing being possible by observing the interlocus heterodimers. Family studies demonstrate that TPI-3* 100 and *103 are of autosomal location and are inherited in a Mendelian fashion. TPI-3* variation can also be typed in adipose fin tissue, allowing nondestructive tissue sampling. Three loci are also active in brown trout, Salmo trutta, with two individuals being homozygous for TPI-3*, as are a small number of S. salar from eastern Canada. The presence of this additional variable allozyme locus in S. salar is important, since genetic studies in that species have been limited by the low level of allozyme variability detectable.